Thank you for sharing this hugely common sense approach to healthy eating - and just as importantly a healthy lifestyle. Correct me if I'm wrong but the essence seems to me be: eat lots of (ideally diverse and organic) plants and be happy.
You are absolutely right! And far more concise than I was!
Even the most current trials on fermented foods and gut health are too short term, don’t demonstrate how how such diets modulate immune responses, and are often tested on healthy adults, so finds might not apply to other groups. Basically, even what we think we know, when we look closer, we aren’t sure about 😂
Thanks for sharing so much of your research. I’m trying to repair my gut after a long course of antibiotics and, living with a sceptical scientist, have often wondered what the research actually shows. Like you I am careful of both modern research and ancient wisdom and try to listen to my body to decide what is helping. Luckily my sceptical scientist makes amazing sauerkraut because we love the flavour
I’m working hard to develop my forest gardening at home to provide me with diverse organic fruit, vegetables and herbs as I absolutely believe they are the key to good health. Including the activity of gardening and the mental health benefits of being outdoors in beautiful surroundings
A pot of homemade sauerkraut and some beautiful, knobbly, homegrown vegetables and fruits and I think you’re on to a winner. I wish you the best with recovery.
Thanks. I’ve also added in a couple of squares daily of organic dark chocolate as ‘medicinal’. I’m not sure of the evidence but it cheers me up and that medicine enough for me
I make my own kefir from kefir grains. I LOVE milk, but a few years ago, milk didn't love me anymore, so I had to give it up. But kefir allows me to drink milk again, and at age 72, I need the calcium and other good stuff kefir provides. Besides that, I LOVE milk! And that's really what it's all about for me. Would I like people I know to jump on the bandwagon? Absolutely! But no one is quite as excited about it as me...
Oh believe me, I’m just as excited as you! Fermentation certainly helps make foods more digestible, especially in the breakdown of lactose. The same is true for cultured butters and aged cheeses. Thank goodness for bacteria!
I’m quite as excited about milk kefir as you - it changed my life and that is no exaggeration. I spend my days on instagram showing how easy it is to make it!
Hi Sam! Would love to message you about guest-posts, I'm a microbiome scientist and dietitian - and I know my readers on my substack Second Brain would be fascinated hear more about fermenting too and your recipes?
Also...on the topic of the science of fermented foods and gut health, there's a randomised control trial (so causal evidence!) that shows that six servings of fermented foods a day boosted microbial diversity (a sign of a healthy gut) and lowered certain markers of inflammation. Thought it might interest you :) DOI: 10.1016/j.cell.2021.06.019
Fascinating, thank you for sharing! I’m interested in guest-posting if you’ll have me.
Making my way through the study you linked to:
“These data suggest that the increase in microbiota diversity in the high-fermented food diet arm was not primarily due to consumed microbes, but rather a result of shifts in or new acquisitions to the resident community. These data support that fermented food consumption has an indirect effect on microbiota diversity, rendering the microbiota receptive to the incorporation or increased representation of previously undetected strains within the gut.”
It also lists the main sources of fermented food in the study as yoghurt and vegetable brine. Which I suppose you’d have to restrict to if you wanted to avoid overlap with fibre. But I’d be suspicious of results following a diet of hammering gut microbiota with salty liquid, followed by a high fat animal protein that DIDN’T show a difference in final results.
I’m interested to know what a serving constitutes and how they think they’ve singled the results down to fibre specifically when the dietary changes in test subjects are listed as: High-fiber diet participants increased their intake of soluble and insoluble fiber, carbohydrates, vegetable protein, and had a modest increase in calories, along with increases in iron, magnesium, potassium, vitamin C, and calcium. These participants also decreased their consumption of animal protein and sodium.
I wonder how they isolated the results from the other variables, such as decreasing animal protein.
Very interesting is this part: “A 2-week food exchange study in which African Americans consumed a rural African diet and rural Africans ate a typical African American diet revealed measurable changes to the microbiota and markers of cancer risk despite the brevity of the dietary intervention.”
I’ll continue reading, and I’m finding it fascinating. Thank you for sharing! :)
Always fun chatting microbes! Would be great to chat further, do send me a message if you're interested, and your recipes are always tantalisingly beautiful.
So this study explored how two diets - high-fibre and high-fermented foods - impacted the gut microbiome and immune system over 10 weeks.
The high-fibre diet improved the gut’s ability to process fibre and make beneficial molecules like short-chain fatty acids, which support gut and overall health. It also slightly reduced inflammation, but microbiota diversity didn’t change much - likely because more time is needed than 10 weeks to clearly see these shifts.
For the high-fermented-food diet they ate a variety of fermented foods, totalling six servings daily (e.g., 6 oz yogurt or kefir, 2 oz vegetable brine, ¼ cup kimchi). This had quicker effects, increasing microbiome diversity and reducing certain inflammation markers. Despite including some fermented brine drinks, the researchers showed that salt intake didn’t increase. So the study shows how diets are good for gut and immune health.
But yes - to sign back to your main post - we need so much more research in this area. Kombucha for example, we have no studies in humans yet to show it helps health.
Great to chat, and hope we can cook something up together here soon!
Interesting! How I understand it, the study said both diets observed little difference from native microbiota but slightly made all participant’s biomes more similar to others within their grouping. They also make a point to say that results in the high fermented foods group were not primarily due to consumed microbes, but has an indirect effect on microbiota diversity, rendering the microbiota receptive to the incorporation OR increased representation of previously undetected strains within the gut.
In other words, we don’t know why. Which is my main point, and why I suggest moderation and diversity when it comes to diet :)
My concern is that some people will see a 10 week randomised control trial, interpret the results with favourably, and tell others that eating fermented foods are proven to have longterm health benefits.
Regarding salt, it was noted that despite increased salt in the diet, sodium levels remained the same. Correct me if I’m wrong, but this would be expected? As an increase in sodium, in a short amount of time, in a healthy individual, wouldn’t show up. But chronically, over a long period of time, would have an effect.
Excuse my layman perspective on this! As I stress, I’m not a doctor 😂
You’re very welcome! I’m glad you found it useful. I don’t usually share this side of my work as I find the debate around health and the money surrounding it far less enjoyable than the art of fermenting, cooking, and growing great food. And of course, sharing it with you.
This was such an interesting read, and a reminder that there is simply no magic bullet.i had a friend recently say that she was going to start taking her vitamins because she wanted to get healthy. Sigh! Not the answer! A diversity of real food choices is though, and because fermented foods can be so delicious and diverse, they're a part of the answer for me, even if the hype isn't entirely warranted or proven.I love that Dr. Emily responded to you. Her posts are so thoughtful-provoking too.
Exactly! The tricky part is just how complex the subject is. We thought it was hard when we imagined a human as an individual, let alone as a collection of walking ecosystems! And whilst we might have suggestions for food that make a healthy gut microbiome, another doctor with a different specialty might say the same foods will increase our risk of heart disease or stroke. It If I ate as much yoghurt as some recommend for gut health, my skin would break out and my breathing would suffer. It’s all about balance and not relying too heavily on any one food or advice.
Though I am sorry to have had my bubble burst, I've always been aware that my true reason for fermenting my veg was the pure exhilaration of taste and texture.
Felt smug at the idea that it was also like taking a homemade supplement (something I don't otherwise do), but there you go!
There is a very recent (low level) study that indicates eating large amounts of dairy yoghurt (which I know you won’t want to do) and drinking fermented vegetable brine 6 times a day, can subtly shift your microbiome. However, the amount of fat and salt this would increase will likely cause cardiologists to cry. So it depends what your focus is. I opt for balance and loads of fibre. It has been found that fibre increases the health and abundance of all your native microbes. So perhaps instead of focusing on adding more, we should focus on looking after those we have. Incidentally, no study has found evidence that eating loads of fermented foods in a burst has a long lasting effect. For all we know, things might well return to an equilibrium.
I can tell you that the time I downed half of a fat jar of fermented cucumber brine because it was delicious and it would have been good for my microbiome, I was upset (so to speak) for two days.
A spoonful in a Bloody Mary is still ok, but my straight brine drinking days were put to a stop there and then.
So now the question is: we’ve always been told that the healthiest and oldest individuals were to be found among the Bulgarian (lots of yogurt), the Japanese (lots of miso and tamari) and the Sardinian (lots of raw cheese). Which of course are all fermented foods.
This information has been based on how old these people managed to get - which seems like a pretty sound benchmark.
Do the researches you refer to ever mention these… clichés?
Wise words. Thank you for spending the time to put together such a thorough thoughtful article. Annoyingly everything is more complex when you start investigating foods and us humans do so prefer simple solutions!
Thanks for sharing your thoughts and navigating succinctly through the plethora of claims and opinions about us ‘being’ what we eat. I suspect the statement is true, in part at least, but I suspect there’s a whole level of interactivity beyond the microscopic that we haven’t even imagined yet (quantum microbial activity anyone?).
I once had a wonderful conversation with a most eminent medical specialist who concluded that doctors don’t know ‘best’ and that at best, their practices were more dark arts or even a good gamble rather than based on proven factual knowledge!
Sadly we see daily references by people (sometimes in positions of high influence) who ‘know’ all the answers and wilfully return will take money in return for their ‘’. Personally I find these snake-oil health rackets abhorrent and so am always drawn to people who simply share their truth and set a personal example of doing what they need to do to balance their mind, body and spirit, often by simply seeing themselves as a part of nature rather than apart.
You’re a beacon of refreshingly healthy light Sam and with nuggets like the statement below I hope you’ve made all of us here stop and think. You’ve posed a beautifully elegant question that perhaps we should all be considering as part of our daily practice…
It’s the whole diet and lifestyle working synergistically together which help the microbiome, and us. Reductionism, pointing at one food is bonkers. Studies on the Mediterranean diet in humans keep showing us it’s all about the whole dietary pattern and all the substances within that working as teams together for good effect.
Thank you so much for this! I couldn't agree more. I was histamine intolerant most of my life (although I grew up on a vegetable farm) even though no one knew what that was. I found fermenting my own food for shorter times helped my health more than an elimination diet. Sometimes I think the stess we make about being unhealthy, makes us more unhealthy! I read a lot of abstracts and try to wrap my head around the science, but at the end of the day, I am happier spending time outside in my garden and in the woods forgaging a bit.
I ferment because it is a fun discovery and makes the daily work novel. I ferment because I love to do it and it is a smart, low energy way to maintain my vegetables for the winter months and it adds a lot of flavour to our plant based diet. Making my own koji was a game changer too, although my family isn't always mega open about my experiments. They have laughed at me for years, and yet, my husband that suffers from an inherited autoimmune psoriasis arthritis has had the best bloodwork of his life since he has limited himself to my cooking rather than eating out at work.
So, I am thrilled with your book and trying to expand on the vocabulary that I have under my belt. I have found that the change to eating fermented foods should be a very slow one and the body doesn't want radical overnight differences rather gradual easing in.
I'm a physician and I appreciate and approve this wise article.
I have one objection though, and that's regarding your one-size-fits-all stance on protein. Athletes and the elderly like myself require more protein. We oldsters develop muscle wasting (sarcopenia) as we age and studies have shown that a diet high in bioavailable proteins can actually prevent and even reverse sarcopenia. I aim for 60 grams a day based on my age and BMI.
Hi Michael, thank you for the feedback. My comment regarding protein wasn’t to say there aren’t cases where an increase might be beneficial to certain groups (along with lifestyle and exercise), just that generally people over estimate how much is required for the average adult living a modern western diet. And from a gut health perspective, they’d possibly be healthier by swapping some out for vegetables and fibre.
Hey! I just received "The Self-Sufficiency Garden" in the mail and I can hardly put it down. Thanks to both of you. Y'all are making a difference in the world.
Thank you for sharing this hugely common sense approach to healthy eating - and just as importantly a healthy lifestyle. Correct me if I'm wrong but the essence seems to me be: eat lots of (ideally diverse and organic) plants and be happy.
You are absolutely right! And far more concise than I was!
Even the most current trials on fermented foods and gut health are too short term, don’t demonstrate how how such diets modulate immune responses, and are often tested on healthy adults, so finds might not apply to other groups. Basically, even what we think we know, when we look closer, we aren’t sure about 😂
Thanks for sharing so much of your research. I’m trying to repair my gut after a long course of antibiotics and, living with a sceptical scientist, have often wondered what the research actually shows. Like you I am careful of both modern research and ancient wisdom and try to listen to my body to decide what is helping. Luckily my sceptical scientist makes amazing sauerkraut because we love the flavour
I’m working hard to develop my forest gardening at home to provide me with diverse organic fruit, vegetables and herbs as I absolutely believe they are the key to good health. Including the activity of gardening and the mental health benefits of being outdoors in beautiful surroundings
A pot of homemade sauerkraut and some beautiful, knobbly, homegrown vegetables and fruits and I think you’re on to a winner. I wish you the best with recovery.
Thanks. I’ve also added in a couple of squares daily of organic dark chocolate as ‘medicinal’. I’m not sure of the evidence but it cheers me up and that medicine enough for me
There is a lot of evidence that if it makes you less stressed then it practically is a medicine. And that's good enough for me.
I make my own kefir from kefir grains. I LOVE milk, but a few years ago, milk didn't love me anymore, so I had to give it up. But kefir allows me to drink milk again, and at age 72, I need the calcium and other good stuff kefir provides. Besides that, I LOVE milk! And that's really what it's all about for me. Would I like people I know to jump on the bandwagon? Absolutely! But no one is quite as excited about it as me...
Oh believe me, I’m just as excited as you! Fermentation certainly helps make foods more digestible, especially in the breakdown of lactose. The same is true for cultured butters and aged cheeses. Thank goodness for bacteria!
I’m quite as excited about milk kefir as you - it changed my life and that is no exaggeration. I spend my days on instagram showing how easy it is to make it!
Hi Sam! Would love to message you about guest-posts, I'm a microbiome scientist and dietitian - and I know my readers on my substack Second Brain would be fascinated hear more about fermenting too and your recipes?
Also...on the topic of the science of fermented foods and gut health, there's a randomised control trial (so causal evidence!) that shows that six servings of fermented foods a day boosted microbial diversity (a sign of a healthy gut) and lowered certain markers of inflammation. Thought it might interest you :) DOI: 10.1016/j.cell.2021.06.019
Fascinating, thank you for sharing! I’m interested in guest-posting if you’ll have me.
Making my way through the study you linked to:
“These data suggest that the increase in microbiota diversity in the high-fermented food diet arm was not primarily due to consumed microbes, but rather a result of shifts in or new acquisitions to the resident community. These data support that fermented food consumption has an indirect effect on microbiota diversity, rendering the microbiota receptive to the incorporation or increased representation of previously undetected strains within the gut.”
It also lists the main sources of fermented food in the study as yoghurt and vegetable brine. Which I suppose you’d have to restrict to if you wanted to avoid overlap with fibre. But I’d be suspicious of results following a diet of hammering gut microbiota with salty liquid, followed by a high fat animal protein that DIDN’T show a difference in final results.
I’m interested to know what a serving constitutes and how they think they’ve singled the results down to fibre specifically when the dietary changes in test subjects are listed as: High-fiber diet participants increased their intake of soluble and insoluble fiber, carbohydrates, vegetable protein, and had a modest increase in calories, along with increases in iron, magnesium, potassium, vitamin C, and calcium. These participants also decreased their consumption of animal protein and sodium.
I wonder how they isolated the results from the other variables, such as decreasing animal protein.
Very interesting is this part: “A 2-week food exchange study in which African Americans consumed a rural African diet and rural Africans ate a typical African American diet revealed measurable changes to the microbiota and markers of cancer risk despite the brevity of the dietary intervention.”
I’ll continue reading, and I’m finding it fascinating. Thank you for sharing! :)
Always fun chatting microbes! Would be great to chat further, do send me a message if you're interested, and your recipes are always tantalisingly beautiful.
So this study explored how two diets - high-fibre and high-fermented foods - impacted the gut microbiome and immune system over 10 weeks.
The high-fibre diet improved the gut’s ability to process fibre and make beneficial molecules like short-chain fatty acids, which support gut and overall health. It also slightly reduced inflammation, but microbiota diversity didn’t change much - likely because more time is needed than 10 weeks to clearly see these shifts.
For the high-fermented-food diet they ate a variety of fermented foods, totalling six servings daily (e.g., 6 oz yogurt or kefir, 2 oz vegetable brine, ¼ cup kimchi). This had quicker effects, increasing microbiome diversity and reducing certain inflammation markers. Despite including some fermented brine drinks, the researchers showed that salt intake didn’t increase. So the study shows how diets are good for gut and immune health.
But yes - to sign back to your main post - we need so much more research in this area. Kombucha for example, we have no studies in humans yet to show it helps health.
Great to chat, and hope we can cook something up together here soon!
Interesting! How I understand it, the study said both diets observed little difference from native microbiota but slightly made all participant’s biomes more similar to others within their grouping. They also make a point to say that results in the high fermented foods group were not primarily due to consumed microbes, but has an indirect effect on microbiota diversity, rendering the microbiota receptive to the incorporation OR increased representation of previously undetected strains within the gut.
In other words, we don’t know why. Which is my main point, and why I suggest moderation and diversity when it comes to diet :)
My concern is that some people will see a 10 week randomised control trial, interpret the results with favourably, and tell others that eating fermented foods are proven to have longterm health benefits.
Regarding salt, it was noted that despite increased salt in the diet, sodium levels remained the same. Correct me if I’m wrong, but this would be expected? As an increase in sodium, in a short amount of time, in a healthy individual, wouldn’t show up. But chronically, over a long period of time, would have an effect.
Excuse my layman perspective on this! As I stress, I’m not a doctor 😂
Thanks Sam, a really informative read. Appreciate you taking the time to collate the information and write it up.
You’re very welcome! I’m glad you found it useful. I don’t usually share this side of my work as I find the debate around health and the money surrounding it far less enjoyable than the art of fermenting, cooking, and growing great food. And of course, sharing it with you.
Totally agree. There are far too many false claims out there along with a lack of honesty.
This was such an interesting read, and a reminder that there is simply no magic bullet.i had a friend recently say that she was going to start taking her vitamins because she wanted to get healthy. Sigh! Not the answer! A diversity of real food choices is though, and because fermented foods can be so delicious and diverse, they're a part of the answer for me, even if the hype isn't entirely warranted or proven.I love that Dr. Emily responded to you. Her posts are so thoughtful-provoking too.
Exactly! The tricky part is just how complex the subject is. We thought it was hard when we imagined a human as an individual, let alone as a collection of walking ecosystems! And whilst we might have suggestions for food that make a healthy gut microbiome, another doctor with a different specialty might say the same foods will increase our risk of heart disease or stroke. It If I ate as much yoghurt as some recommend for gut health, my skin would break out and my breathing would suffer. It’s all about balance and not relying too heavily on any one food or advice.
Great article, and such a pleasant read.
Though I am sorry to have had my bubble burst, I've always been aware that my true reason for fermenting my veg was the pure exhilaration of taste and texture.
Felt smug at the idea that it was also like taking a homemade supplement (something I don't otherwise do), but there you go!
There is a very recent (low level) study that indicates eating large amounts of dairy yoghurt (which I know you won’t want to do) and drinking fermented vegetable brine 6 times a day, can subtly shift your microbiome. However, the amount of fat and salt this would increase will likely cause cardiologists to cry. So it depends what your focus is. I opt for balance and loads of fibre. It has been found that fibre increases the health and abundance of all your native microbes. So perhaps instead of focusing on adding more, we should focus on looking after those we have. Incidentally, no study has found evidence that eating loads of fermented foods in a burst has a long lasting effect. For all we know, things might well return to an equilibrium.
I can tell you that the time I downed half of a fat jar of fermented cucumber brine because it was delicious and it would have been good for my microbiome, I was upset (so to speak) for two days.
A spoonful in a Bloody Mary is still ok, but my straight brine drinking days were put to a stop there and then.
So now the question is: we’ve always been told that the healthiest and oldest individuals were to be found among the Bulgarian (lots of yogurt), the Japanese (lots of miso and tamari) and the Sardinian (lots of raw cheese). Which of course are all fermented foods.
This information has been based on how old these people managed to get - which seems like a pretty sound benchmark.
Do the researches you refer to ever mention these… clichés?
Wise words. Thank you for spending the time to put together such a thorough thoughtful article. Annoyingly everything is more complex when you start investigating foods and us humans do so prefer simple solutions!
Thanks for sharing your thoughts and navigating succinctly through the plethora of claims and opinions about us ‘being’ what we eat. I suspect the statement is true, in part at least, but I suspect there’s a whole level of interactivity beyond the microscopic that we haven’t even imagined yet (quantum microbial activity anyone?).
I once had a wonderful conversation with a most eminent medical specialist who concluded that doctors don’t know ‘best’ and that at best, their practices were more dark arts or even a good gamble rather than based on proven factual knowledge!
Sadly we see daily references by people (sometimes in positions of high influence) who ‘know’ all the answers and wilfully return will take money in return for their ‘’. Personally I find these snake-oil health rackets abhorrent and so am always drawn to people who simply share their truth and set a personal example of doing what they need to do to balance their mind, body and spirit, often by simply seeing themselves as a part of nature rather than apart.
You’re a beacon of refreshingly healthy light Sam and with nuggets like the statement below I hope you’ve made all of us here stop and think. You’ve posed a beautifully elegant question that perhaps we should all be considering as part of our daily practice…
‘Where do I stop and the world begin?’
May your continuum continue!
Great piece!
It’s the whole diet and lifestyle working synergistically together which help the microbiome, and us. Reductionism, pointing at one food is bonkers. Studies on the Mediterranean diet in humans keep showing us it’s all about the whole dietary pattern and all the substances within that working as teams together for good effect.
Thank you so much for this! I couldn't agree more. I was histamine intolerant most of my life (although I grew up on a vegetable farm) even though no one knew what that was. I found fermenting my own food for shorter times helped my health more than an elimination diet. Sometimes I think the stess we make about being unhealthy, makes us more unhealthy! I read a lot of abstracts and try to wrap my head around the science, but at the end of the day, I am happier spending time outside in my garden and in the woods forgaging a bit.
I ferment because it is a fun discovery and makes the daily work novel. I ferment because I love to do it and it is a smart, low energy way to maintain my vegetables for the winter months and it adds a lot of flavour to our plant based diet. Making my own koji was a game changer too, although my family isn't always mega open about my experiments. They have laughed at me for years, and yet, my husband that suffers from an inherited autoimmune psoriasis arthritis has had the best bloodwork of his life since he has limited himself to my cooking rather than eating out at work.
So, I am thrilled with your book and trying to expand on the vocabulary that I have under my belt. I have found that the change to eating fermented foods should be a very slow one and the body doesn't want radical overnight differences rather gradual easing in.
Excellent Sam.
I'm a physician and I appreciate and approve this wise article.
I have one objection though, and that's regarding your one-size-fits-all stance on protein. Athletes and the elderly like myself require more protein. We oldsters develop muscle wasting (sarcopenia) as we age and studies have shown that a diet high in bioavailable proteins can actually prevent and even reverse sarcopenia. I aim for 60 grams a day based on my age and BMI.
Hi Michael, thank you for the feedback. My comment regarding protein wasn’t to say there aren’t cases where an increase might be beneficial to certain groups (along with lifestyle and exercise), just that generally people over estimate how much is required for the average adult living a modern western diet. And from a gut health perspective, they’d possibly be healthier by swapping some out for vegetables and fibre.
Hey! I just received "The Self-Sufficiency Garden" in the mail and I can hardly put it down. Thanks to both of you. Y'all are making a difference in the world.
Aw thanks! I’m glad you’re enjoying it so much