Gut Bacteria Shift Quickly After Changes in Diet, Study Shows

[locarb4avr]

==We are not alone==

Number and type of gut microbes shifted within a day of eating plant- or animal-based foods exclusively

December 11, 2013 RSS Feed Print

By Brenda Goodman
HealthDay Reporter

http://health.usnews.com/health-news/news/articles/2013/12/11/gut-bacteria-shift-quickly-after-changes-in-diet-study-shows

[inflammabl]

Nice article.

"Cirillo said it was also intriguing how fast the microbiome seemed to recover. The study found that gut bacteria were back to business as usual about a day after people stopped eating the experimental diet."

What about after several months on a different diet? Does the bacteria recover?

[aj_cohn]

Chris Kresser recently had an interesting podcast with Dr. Jeff Vietch, head of the "American Gut" crowdsourced research project about the gut microbiome. One of my takeaways was that pronounced shift in gut bacteria of low-carbers that made the colon have an alkaline pH rather than the normal acidic pH, thereby giving toxic bacteria the chance to colonize. He added that he didn't have enough long-term data (although he has low-carbers in his study population) to say what the ultimate effects of the shift in flora cause, but the short-term results were unsettling.

[teaser]

http://chriskresser.com/you-are-what-your-bacteria-eat-the-importance-of-feeding-your-microbiome-with-jeff-leach

Jeff Leach: But I lump it all together with anything that escapes digestion in the upper GI tract and ends up in your colon and is available for fermentation, and it’s a lot of things besides just dietary fiber. But I’m concerned about it for the exact reasons that you are. We don’t have the data. Nobody has done any nice clinical controlled trials, but when you starve the bacteria, you may see an increase in mucin degraders like Akkermansia and a few other ones. That shift in the pH is going to provide opportunities for pathogens to maybe bloom up that may cause some down-the-road, long-term problems. But again, maybe not. Nobody knows for sure, but if you’re shifting that pH and you’re not fermenting, you’re opening the pathogen’s door. It’s going to take a long time to unwind this, but I think the more low carb people we can get in the study, we can contribute to the conversation at least to the point where it can serve as a baseline for maybe more controlled clinical kinds of studies.

I'd guess that there probably isn't a ph you could have in your colon that wouldn't be ideal for [/I]some[I] pathogen.

If Paul Jaminet is right, a zero carb diet should decrease mucin-degraders... no mucin, no mucin degraders. :lol:

You would think that, left to their own devices, a bacterial population would take advantage of whatever food was available to it. I looked up Akkermansia, they're 1-3 percent of the gut bacteria population from infancy.

I saw a mention of Akkermansia in wikipedia that mentioned a possible link to diabetes. Uh oh. So then I googled this;

http://www.gutmicrobiotaforhealth.com/t/akkermansia-as-a-target-for-obesity-authors-explained-116

3) What were the main findings?

i. Obesity is associated with a decrease in the abundance of Akkermansia muciniphila in gut microbiota.
ii. Akkermansia muciniphila is able to cross-talk with the intestinal epithelium to control gut barrier functions in the pathophysiology of obesity. We show for the first time that obesity is associated with a decrease in the mucus layer thickness recovering epithelial cells. Interestingly, Akkermansia muciniphila is the dominant human bacterium that abundantly colonizes this nutrient-rich environment. We found that living Akkermansia muciniphila was able to control mucus layer production by the host and restore mucus layer thickness in high-fat diet-induced obese mice thereby reducing gut permeability.
iii. Akkermansia muciniphila decreases lipid storage and increases lipid oxidation in high-fat diet obese mice.
iv. Akkermansia muciniphila counteracts inflammation associated to obesity.
v. Akkermansia muciniphila controls high-fat diet-induced obesity and type-2 diabetes.

Of course, I suspect Jeff Leach sort of pulled that guess about Akkermansia out of the air. (I was tempted to say he pulled it out of the same place that fecal samples come from, but I restrained myself. Obviously not very well).

So Leach's guess about an increase in Akkermansia could just as easily lead to a healthier, less permeable gut. The way he words it, though, before I looked it up I thought Akkermansia were some sort of pathogen.

I have no idea if adding resistant starch or fiber would improve my gut flora, make it worse, or affect it in a way that had no effect on my health whatsoever. So I just don't worry about it. I eat spinach because I like it.

[inflammabl]

Okay, here is one problem I have with gut flora arguments. Say a certain food or foods increase a healthy flora. Say dairy, for example. So by adding dairy, we increase that flora. We don't know we are doing that but we are. A few weeks later we take stock of how we feel and maybe we've lost some weight. In our minds we think "Oh, dairy is good."

Is that wrong? No! For that person with that gut bacteria dairy is good. So I don't think first order gut bacteria arguments really help us all that much.

Now this is not meant to pooh pooh all gut bacteria arguments. I personally have a theory that at least some stalls are caused by a loss in some gut bacteria. That is another reason why I don't reject CKD out of hand. One day of "carb ups" every week might keep the original gut bacteria alive and help prevent stalls. Maybe.

[rightnow]

I would genuinely love to see an experiment where people used guided meditation (slightly altered states of mind, focus on the bacteria) to harm or encourage certain bacteria. Maybe even certain types, if there was a way to 'show' the body one (e.g. let a person touch something that has that bacteria, for the subconscious, name it, and then use that name in the meditation). Hypnosis research (prior to the topic falling out of library and being historically revised to a kinder, gentler sort of art or ignored/mocked entirely) is pretty amazing even on things that seem far more powerful. I seriously wonder if our state of mind in general, let alone on purpose, can affect our gut bacteria.

For that matter, various frequencies are known to kill some things and not others. You can get the vibratory DNA frequencies to kill all kinds of pathogens with EM techs (some researchers sell that. I mean legit mainstream type researchers here, not fringe-field folks). But a 'small' amount of a freq is strengthening, not shattering. Could we get the freqs of various gut bacteria? Then we could make a machine (or even a simple body-touch antenna ala FreX and Carmi's Blanket) that might affect their number.

I wish there were some way for laymen researchers to measure such a thing themselves as I bet we'd learn more of direct use to us in two years than official science will in the next ten, sigh.

PJ

[teaser]

So I wonder what counts as a probiotic for beneficial mucin-munching bacteria? Raw, slimy seafood?

4) What are the limitations?

Although we have discovered several putative targets (e.g., the endocannabinoid system, Reg3 gamma), more studies are needed to unravel metabolites and molecular targets involved in the cross-talk between Akkermansia muciniphila and epithelial host cells to control obesity.

If Akkermansia did promote mucin formation in the gut through the endocannabinoid system, and not just locally... it might work through some peptide or hormones they put out, where there's a peptide or hormone, there's a receptor, and where there's a receptor there's liable to be some less friendly bacteria that puts out antagonisers for that receptor. All it would have to do is block signals from Akkermansia, and the mucin gets degraded, and you have a host that's compromised and perhaps more prone to eating the diet that's good for the bad bacteria.

Some of the most beneficial bacteria living off of us, rather than our food makes a certain sense, since this is an aspect of gut health that our bodies would get a "vote" in across a broad spectrum of sensible diets--potentially all the way from Inuit to Kitivan.

[rightnow]

The really creepy side of me is totally fascinated with the idea that what we think and choose, food or otherwise, may actually be somewhat influenced by what teeeeny tiny little entities leeching off our innards want us to do.

Like some super tiny aliens in Star Trek once, they probably think of us as "ugly sacks of mostly water."

But they can talk to our body in subtle insidious ways and we don't even know we're influenced by them.

Oooooooooh. Eeeeeeeeew.

PJ

[inflammabl]

I've been trying to harness the power of my midichlorians since I was eleven years old. So far no success.

[inflammabl]

......more studies are needed to unravel metabolites and molecular targets involved in the cross-talk between Akkermansia muciniphila and epithelial host cells to control obesity.....

I think this is research quicksand.

[teaser]

Might be. But when they went looking for a way that bacteria might cause leaky gut, they came back with zonulin. It's very plausible that the bacteria might encourage us to produce more of their food source. I think they should risk wasting a bunch of money on this. Stop funding epidemiologists, fund stuff like this.

[inflammabl]

Correlation is not causation but it's a darn good start. So epidemiologists have their uses.

As far as leaky gut and other things that interfere with health, I agree 100%. What I would really like to see is how gut bacteria composition evolves over months on a keto diet. I think I said this a few months ago but I wonder if weight loss could be improved by re-injection ( :eek: ) of the "normal" gut bacteria.

[teaser]

Okay, so I wondered if Leach's mention of the possibility was just a shot in the dark guess or not--because if a low-carb diet meant higher Akkermansia, that could be a plus for low-carbohydrate. I got this over at FreetheAnimal, in some respects resistant-starch-central in the low carb/paleo community.

RESULTS AND DISCUSSION: Fermentable dietary fibre decreased weight gain, liver fat, cholesterol and triglyceride content, and changed the formation of SCFAs. The high-fat diet primarily reduced formation of SCFAs but, after a longer experimental period, the formation of propionic and acetic acids recovered. The concentration of succinic acid in the rats increased in high-fat diets with time, indicating harmful effect of high-fat consumption. The dietary fibre partly counteracted these harmful effects and reduced inflammation. Furthermore, the number of Bacteroides was higher with guar gum, while noticeably that of Akkermansia was highest with the fibre-free diet.

Of course, this doesn't mean that low carb would increase Akkermansia. But if fiber can reduce Akkermansia, and if the Akkermansia guys are at all right about this (if, if, if) then there's a mechanism where some fibers might reduce Akkermansia, and as a result increase gut permeability over time, and maybe obesity and type II diabetes, and potentially all sorts of auto-immune diseases as well. Of course, the prebiotics had the opposite results in the mouse studies where Akkermansia was pegged as possibly beneficial. It's possible we need to be careful about attempting to up our fiber intake. Which fiber? Guar gum had a short-term effect of decreasing inflammation--that's very nice, but what if in the long-term, that decrease in Akkermansia continued, and led to leaky gut?

Bill at caloriesproper has a blog post on low-carb diets and gut bacteria.

http://caloriesproper.com/

Where, basically, a meat-only diet caused an increase in the Bacteriodete/firmicute ratio vs a plant-based diet. This is supposedly a good thing. Bile-munching bacteria also increased, supposedly a bad thing, and this is what the researchers chose to trumpet.

An alkaline gut might make it a little easier on certain pathogenic bacteria. That's why a lion or a polar bear's immune/hormonal/etc. systems work so hard, and are so flexible, to deal with the pathogens most likely to show up in their carnivore digestive systems. And a cow is adapted to the most likely pathogens that it's system would be exposed to. In mice, it's been shown that colitis increases with a high-fat diet if IL-10 is knocked out--that is, knock out part of the body's natural defense against a pathogen that you'd expect to increase when you eat that particular, high-fat diet, and suddenly, bile-munching bacteria are dangerous, where without the knock-out, they might be harmless or even beneficial.

Knock out a part of our system that's necessary for our bodies to see some raved-about beneficial bacteria as friendly--and suddenly those bacteria may be pathogenic. This may be true of any beneficial bacteria--they're seen as an infection, and the body reacts with an inflammatory response.

I think giving hard advice based on this stuff would be as foolhardy as giving advice on diet/statin intake based on a 1917 understanding of blood cholesterol. :lol: