Anti-Inflammatory Diet

All health care starts with diet. My recommendations for a healthy diet are here:
Anti-Inflammatory Diet and Lifestyle.
There are over 190 articles on diet, inflammation and disease on this blog
(find topics using search [upper left] or index [lower right]), and
more articles by Prof. Ayers on Suite101 .

Saturday, January 25, 2014

Milk, Kefir and Gut Flora

Milk is a dramatic manipulator of gut flora.  It is a baby’s first food and provides necessary nutrients, but of equal importance, it crafts a community of gut microorganisms that develop the gut and immune system of babies.  Breastfed babies receive protein, fat and sugar, but they also coat their tiny stomachs and even their respiratory system with maternal lymphocytes and bacteria.  The major carbohydrate in breast milk is lactose, but there are other prebiotic oligosaccharides (HMO, human milk oligosaccharides) and polysaccharides (GAGs, glycosaminoglycans) related to heparin and chondroitin, which carefully limit which bacteria can grow in babies.  There are firm reasons why exclusively breastfed babies have diapers that smell like yogurt and look like curds and whey.

Milk Shows an Exaggerated Interaction between Food and Flora
Evolutionary selection is extreme to favor women who can successfully birth large babies and nurture them for years on breast milk.  Fewer than 5% of women in a general population need medical intervention for gestation, labor, delivery and breastfeeding.  Essentially all women and babies are genetically predisposed to healthy childbirth and milk-based child development.  Clearly, milk is powerful and an examination of the composition of milk should yield information on the interaction between food and gut flora.

Milk is the Prebiotic for Dairy Probiotics
Traditional preservation of cow's milk produces fermented kefir, butter, yogurt, cheeses, etc.  These are all controlled fermentations that begin by converting lactose into lactic acid.  Michael Pollan devoted a major section of his book, Cooked, to the cultural ramification and biology of fermentation.  It seems magical that leaving milk to sour will reproducibly yield a common dairy beverage.  When I taught microbiology, I had students spike raw cow’s milk with E. coli and then measure the decreasing survival of these common gut bacteria that are actively excluded from dairy fermentation.  One of the lessons here is that milk stops the growth of adult gut bacteria and supports the growth of lactic acid bacteria found in baby diapers and used to make fermented dairy products.

Milk is Toxic to Most Microorganisms, until Digested
Enzymes in the stomach convert milk proteins into antimicrobial peptides.  Later in the small intestines, pancreatic proteases digest and inactivate the peptides until they are converted into amino acids and are absorbed by the intestinal microvilli.  Milk is a natural antibiotic and is used ritually for cleansing wounds and pruning hooks.  Ritual fire walking ends by walking through a pool of cow’s milk.  The spread of plant disease in orchards from tree to tree is minimized by dipping pruning tools in milk.  The proteins, fatty acids and carbohydrates in milk kill or inhibit the growth of viruses, bacteria and fungi.  Early studies of the bacteria in breastfed babies showed an exclusive group of lactic acid bacteria and an absence of adult gut bacteria.  Breast milk was shown to contain a “bifidus factor” that selected for baby gut flora and this special ingredient was later shown to consist of a complex mixture of short chains of sugars, human milk oligosaccharides.  Thus, human milk is good for babies, but bad for adult gut flora because most of the protein, fat and carbs are digested and no soluble fiber remains for colon gut flora. 

Formula Kills Baby Gut Flora
Formula made from cow's milk or soy is toxic to baby gut flora and even a single bottle of formula can permanently damage it.  The disastrous impact of formula on gut flora is readily observed in the change to smelly diapers.  Mothers trying to give the best start to their babies can tell when the night nurse got lazy and just fed her baby a bottle of formula!  Use of formula in hospitals instead of mothers nursing or using donor milk greatly increases contamination of babies with deadly strains of hospital bacteria, e.g. C. dificile, and causes necrotising enterocolitis.  The only reason that babies can survive formula and the growth of adult gut flora in the first weeks of life, is that the disrupted gut flora is highly inflammatory and the inflamed gut provides some protection from infection.  Babies are tough, but there is no reason for hospitals to continue to use formula when research clearly shows that it is a risk to the health of babies.  Health concerns are forcing hospitals to encourage exclusive breastfeeding, but more work needs to be done so that donor breast milk is the alternative.

Raw Avoids Risks of Pasteurization and Ultra Homogenization
Milk straight from the udder contains natural dairy probiotics that are fit for a calf.  Dairy probiotics are different from baby gut flora and calves are different from babies, so cow milk is not appropriate for babies.  Processing cow's milk by heat (pasteurization) or extreme mixing to make ultra small fat droplets (homogenization) changes the structure of milk to increase storage shelf life, but the restructuring also produces some health risks for gut and gut flora.  Since leaves are rich in short chain omega-3 fatty acids and seeds are rich in omega-6s, grass fed cows produce healthier (higher 3/6 ratio) milk that may not store as well.

Kefir is a Yeast and Bacteria Biofilm
Commercial dairy products are uniform, because they are made from milk using defined mixtures of pure cultures of bacteria and fungi.  These dairy probiotics can substitute but not replace gut flora, because they can't grow in a healthy gut.  Kefir is a little different, because the kefir grains are biofilms of yeast and bacteria held together by a polysaccharide called kefiran made by a bacterial enzyme that rearranges the glucose and galactose sugar residues of lactose.  The point here is that if you grow your own kefir, you may end up with many species of bacteria and some may be able to contribute to your gut flora.  Many supermarket "kefirs" are just a blend of common dairy probiotics and maybe some inulin, and have no benefits over commercial yogurt.

Dairy products are nutritious, but will not benefit the health of your gut flora (fermented vegetables are a better choice), because they lack soluble fiber and do not contain gut flora, but your gut flora may adapt to the inherently disruptive nature of raw milk.


Unknown said...

What about raw goat milk? Better, worse, same?

Aldert said...

This might be interesting for you,
"that there is much more microbial diversity in -breast- milk than expected, with there being more than 700 different types of bacteria."
Thanks for your helpfull blog!

Anonymous said...

Fascinating post. No wonder my gut flora are up shit creek!! I drank a liter of milk a day until my sixties along with lots of cheese and greek/turkish yoghurt. I have suffered from constipation for over 40 years, and now I know why. I am trying to heal my gut flora but it will be a hard slog I know.


Eve Loftus said...

What about cheese? Hard or soft?Are they helpful to gut flora?

Anonymous said...

So are you saying:

* Drink no milk, raw or any kind
*Raw kefir is good but not as good as fermented vegetables
*Probitotics are a waste of money

Is this correct?

And does alcohol kill gut flora?

Dr. Art Ayers said...

I blush for not discussing raw and the impact of processing. I have made amends and included in the article a reference to my previous article on the subject.

Goat milk was used traditionally by midwives, because it is closer to human milk. Adult gut flora probably adjusts to the milk components that reach the colon, so only large amounts of milk, such as whey shakes, will impact the gut flora.

Whey shakes, by the way, can disrupt the gut flora and facilitate weight gain or loss, since gut flora are involved in weight stability.

I use raw goat cream in my morning coffee. I don't drink milk, but I enjoy all other dairy products.

Remember that lactose intolerance is a commercial gimmick and can be readily cured by eating small amounts of live yogurt daily for several weeks.

Thanks for the comment.

Jonas said...

Just to be clear, this doesn't apply to raw dairy from reputable sources. If the animals are raised on pasture and fed their natural diets with plenty of sunlight, kefir fermented from raw dairy has a great deal of beneficial probiotics and yeasts as referenced here:

The caveat is that you have to know the source you are getting it from. Studies have demonstrated that those who live on farms and drink raw dairy have less allergies. This makes sense since they interact with the soil more, leading to more diverse microflora.

Commercial dairy is a different ballgame because it's processed dairy. The sources are always questionable, and most forms are homogenized and then cultured. Commercial kefir is just as bad as soda.

Dr. Art Ayers said...

Milk bottom line:
Milk is nutritious.
Too much milk bothers adult gut flora.
Raw is better than processed.
Homemade kefir is better than raw.
Dairy probiotics can provide some temporary immune function for damaged gut flora.
Dairy probiotics don't persist in the gut.
Homemade fermented vegetables provide gut bacteria.
Dairy is not essential and should be used briefly as a supplement while gut flora is repaired.
Dairy is also not harmful and butter is more healthful than vegetable oils.
Dairy is for enjoyment.

Melanie said...

Dear Dr Ayers
I just wanted to thank you for your inspiring and life changing blog.I started suffering with what was called psoriatic arthritis when I was 26. It caused me huge pain and suffering and I took doctors advice. That cost me a lot.I am sure the drug therapies- sulphasalazine, NSAIDs,methotrexate,prednisolone and anti TNF did huge damage- I had an emergency operation for what I thought was a benign ovarian cyst when I was 40 resulting in being oopherectomised.When the anti tnf stopped working and I had a major systemic inflammatory episode- I had a steroid infusion and time and energy to do the research.I found your blog.I have followed your advice and now look and feel amazing. My arthritis symptoms gone- I can only tolerate small amounts of starch . Thank you for helping the layperson to put the pieces of the jigsaw together.I appreciate it . Melanie

Melanie said...
This comment has been removed by a blog administrator.
Anonymous said...

I enjoy your blog and really appreciate how you boil all health down to gut health. I've come to believe this myself for awhile now. How does one obtain raw goat cream? I live in a Mid Atlantic state and I can probably get a hold of a semi-automatic weapon easier than raw milk. The baby in the picture from a previous post has been out in the yard eating dirt? Is there benefit to putting soil in capsules and taking them regularly? What about things like toxoplasmosis which can be in dirt and thus on slightly dirty raw vegies which you recommend as a way to get microbes into your gut. Thanks again for your posts. I read a lot of health blogs and while there are great many sciency type people who have blogs very few can reduce dense information into a palatable form for the public as you can.

Nick said...

Hello Dr. Ayers,

Thank you for this post.

I'm wondering if you could expand on your thoughts on whey protein?

From the studies I've read it seems generally healthy. Usually when the relative protein content of the diet increases (e.g. with whey consumption), caloric intake drops.

I've also read that whey has some good anti-microbial properties, and the glutamine is good for the gut.

I don't see many negatives, apart from some fear-mongering about IGF-1 and cancer.

What do you think?



Nick said...

Also, Dr. Ayers and others, you might be interested in this recent paper on unpasteurized milk consumption from the American Academy of Pediatrics:

"However, the benefits of these natural factors [in raw milk] have not been clearly demonstrated in evidence-based studies and, therefore, do not outweigh the risks of raw milk consumption. Substantial data suggest that pasteurized milk confers equivalent health benefits compared with raw milk, without the additional risk of bacterial infections."

majkinetor said...

I was very much intrigued by the probiotic content of the kefir so I looked it up. Probiotics that you can buy OTC are extremely expensive while providing only 1-3 strains in general and small bacterial counts.

There are all sorts of kefir but typically there are 50++ different species present. This depends on the age of the kefir (and temperature) among other things. Vitamin content differ to related to age - there are more B vitamins in aged kefir so it makes sense to let your home made kefir rest in the fridge for few times before consumption. Its also important to say that kefir is not static, that ecosystem adapts to its environment (type of milk, temperature, type of treatment etc.). For more info see this paper: or this site

I think the kefir should be regular part of the diet. Its nutritious, refreshing, delicious and healthy.

Anonymous said...

great run of late, Dr. Ayers. perhaps for your next stab at the mainstream, you'll want to comment on this:

Paul said...

Fantastic article! Kefir is an amazingly healthful food! I have been able to heal up my gut by drinking it everyday for the past 2 years. Have you heard Jordan Rubin’s (the Author of The Maker’s Diet) story? He healed himself of Crohns disease and now has his own company and sells old world style Kefir. Here is a link to an article and video by Jordan about his Kefir. Check it out:

I have issues digesting lactose and I have never had any problems digesting Beyond Organic's kefir or hard RAW cheeses! This stuff is amazing!

Gabriella Kadar said...

Dr. Ayers, for what it's worth, goat milk contains almost no folic acid so it can't be used, on its own, to replace human milk.

Unknown said...

Dr Ayers

I drink raw goat milk and kefir every day. I also use whey concentrate (made from raw grass fed milk - cold processed). I eat a lot of raw veggies, fruit (fresh and frozen) as well as raw grass fed ground beef, a raw egg (including the shell), raw cacao powder, etc.

My gut flora is excellent - no issues with constipation at all.

My skin is very smooth (much much smoother than a 60 year old male has rason to expect)

So - am I doing anything wrong?

Dr. Art Ayers said...

I hope that I didn't confuse anyone by referencing the use of goat milk in desperation by traditional midwives. I think that mother's milk, even if it must be from the milk bank is the only choice for the first six months. Prior to the introduction of solid food, formula provides lasting problems. One bottle of formula is a problem for the baby's gut flora and more bottles make it worse. Mother's milk can only inhibit the inflammatory effects of adult gut flora in the absence of formula.

Thanks for the clarification.

Dr. Art Ayers said...

I don't see any issues. I look at the results. If you are healthy and active, you should be the same at 80.

Whey is a way to destabilize gut flora for weight change. If you have adjust to eating whey, then your gut flora grow in spite of its antimicrobial properties. It's no big deal.

Enjoy your health and thanks for the comments.

Kor said...

Dr. Ayers,
Any thoughts on stimulating proper MMC function in SIBO? How do you move everything through to the colon instead of pooling and fermenting in the small intestine?

Thank you

Anonymous said...

Fascinating ideas. Any thoughts specifically on the role of inflammation and gut bacteria in enlarged adenoids and tonsils in young children suffering from sleep apnea? I would like to avoid surgery for my otherwise very healthy child, and have very little information on alternatives to surgery.

Jo-Ann Dziubek-MacDonald said...

I'm so glad to have found your very helpful blog! Thank you for providing a wealth of information.

I am trying to fix my gut flora to cure my food intolerances and sensitivities. I eat approx 1/2 cup of homemade sauerkraut per day along with taking probiotics(including an infant probiotic formula.) I am not sure if this is enough probiotic food or if it provides enough variety of organisms. So I've checked out recipes in the hopes of fermenting some of my own vegetables.

Many of the recipes I've seen for fermented vegetable utilize whey. Since this is a dairy probiotic would this be considered a temporary probiotic fix? Is it better to use a brine method of fermentation?

Thank you for your help!

Anonymous said...

"Fewer than 5% of women in a general population need medical intervention for gestation, labor, delivery and breastfeeding."

I am interested in knowing where you came up with that number - 5%. As a medical professional who works with childbearing women I can assure you that it is incorrect.

1) Look at our current C/S rate (~30%).
2) The WHO had once estimated that ~10-15% of all births do actually require a C/S - they have since retracted that statement.

Anonymous said...

I'm wondering about your thoughts on water kefir?

Anonymous said...

For the record, it's not impossible to live to 107 years of age while drinking large quantities of raw milk, as Deacon John Whitman did in the 1800s. :)

The Christian patriarch: A memoir of Deacon John Whitman; who died at East Bridgewater, Mass., July, 1842, at the advanced age of 107 years and three months

"If there was any one article of food of which he ever seemed more fond than of another, it was milk. He often made his meal of this, either in its natural state, or boiled or made into milk porridge. There was a period of his life, between the ages of ninety-five and one hundred, when he almost entirely gave up animal food and confined himself to a milk diet. But, he thought that he experienced a clogging effect from his milk, and he returned to the common diet of the family, eating animal food in moderate quantities."

Unknown said...

Can dairy products including from cows be considered a prebiotic for adult flora such as bifidobacteria? Some, ahem, cultures such as the Hazda and Koreans are thought reduced or absent in bifidobacteria due to lack of dairy in the adult diet. Since bifidobacteris appear important for immune modulation and also comprise up to 90% of the breastfed infant gut, it seems dairy may be an important prebiotic.

Unknown said...

I love milk chocolate. Milk is good for health. thank's for share your views.