Ytterligare en podcast av Chris Kresser som har en del intressanta inlägg där han pratar med Jeff Leach från American Gut Project
Jag uppmanar verkligen alla att läsa hela podcasten, eller lyssna till den. Det är en massa intressanta saker som tas upp och jag har bara citerat ett par avsnitt. Jag skulle egentligen vilja citera hela podcasten.
(Jeff) I tell everybody if you’re not having two to three bowel movements a day, then you need to go back and start over, and one of them should be a whopper. If you’re not having that kind of bowel activity, then you’re not fermenting enough – again, assuming you don’t have other issues – and so you need to increase the diversity and quantity of fiber. Why that’s important is when those bacteria ferment that dietary fiber – and again, get it from a lot of sources – it changes the pH of your colon. It makes it more acidic. A lot of opportunistic pathogens are pH sensitive, and so typically as those Ruminococcus and those Blautia and those Bifidobacterium and all those guys go up, you often see the other ones go down. It’s not always a one-for-one, but keeping your colon acidic through fermentation, frequent bowel habit, then all of that stuff leads to improved barrier function with regards to, you know, some people generically call it a leaky gut.
(Chris) What I’ve noticed – and these are just my observations as a clinician, and it’s a relatively small sample size – but almost every patient that walks in my door I do a comprehensive stool analysis, and I use different labs depending on what I’m looking for, but most of them report on the pH. They can give you an idea of what the pH is. They test for butyrate and total short-chain fatty acids and some other markers that give me an idea of what’s happening in terms of their consumption of fermentable fiber and the effects of that fiber on the gut flora. And what I’ve noticed is that many people who are on a ketogenic or very low carb diet – let’s say less than 30 or 40 grams of carbohydrate a day – come back with an alkaline pH in the stool. They have low levels of butyrate or other total short-chain fatty acids and some other markers of dysbiosis. So, that got me thinking and wondering about the potential adverse effects of a very low carb or ketogenic diet from the perspective of gut flora, gut microbiota, and wondering is it that people who are doing the ketogenic diets are not only doing a ketogenic diet, but they’re also just not eating enough plant fiber? And that kind of makes sense. If they’re really trying to limit their carbohydrates, they’re going to be somewhat limited in terms of the variety of vegetables and certainly fruits that they can eat. You can correct me if I’m wrong, but I think I read a blog post of yours a while back that was speculating maybe that 35 or 40 grams of carbohydrate may not be sufficient to reach the levels of bacterial fermentation that you were just talking about.
(Jeff) One of the big things that the low carb diets do is they really drop out the resistant starch in the diet. And what’s interesting about a lot of butyrate producers, Roseburia and these guys and Eubacterium, they’re cross-feeders. For example, you have certain species of bacteria, groups of bacteria that break down whatever, cellulose and hemicellulose, and produce acetate and propionate and all these things, but a lot of the butyrate producers are cross-feeders and they’re feeding off of other activities. So, when I see a very low carb person, I often see not only a huge drop in dietary fiber, but a drop in diversity of dietary fiber and a significant drop in resistant starch, which is a huge source of nutrients for the microbiome as well. Resistant starch is often called the third dietary fiber.
http://chriskresser.com/you-are-what-your-bacteria-eat-the-importance-of-feeding-your-microbiome-with-jeff-leach#comment-86205
2024.11.22 - 15:48:42
