Eat more fiber, feed your microbes - Biology in real life

(Christy Hemphill) #1

This was the current event we did today:

It incorporates lots of good topics like symbiosis, adaptation of species, and the rapid genetic change of microbes.

I try to talk to my kids frequently about nutrition, but it seems like every five minutes the word on the street about what is healthy changes. I thought this article was an interesting take on probiotics because it seems to make more sense from a biological perspective than a lot of what you hear. And it also recommends my personal distillation of all health advice ever, “eat your vegetables.” (Confirmation bias, yes I know. :slight_smile: )

The research discussed said that what was important for a healthy digestive system (more important than adding new probiotics to it through supplements or fermented foods) was what you feed your existing microbiome. And what they eat is fiber.

I find this ironic given the popularity of the Paleo diet, which turns out to be not very Paleo at all. A typical “caveman” was probably mostly vegetarian.

Because the genetic makeup of populations of microbes can change so quickly, what you eat can have a big impact on the adaptation of your personal population of a particular strain of microbes.

This article also wins for the most disgusting sounding recipe I’ve seen this week.

(Phil) #2

Good article, certainly agree with the need for more fiber. That is probably my number one dietary recommendation to patients. ( Just don’t be like the patient I told to eat more fiber and she came back and said, " I switched from potato chips to Fritos, what more can I do?")
I does amuse me that the local natural food store sells “prebiotics” which basically is just “food.”

(Laura) #3

Thanks for sharing – my husband’s been having a whole host of digestive issues over the last few years, and has recently started a probiotic – but our most recent resolution has been mainly to eat more vegetables. It’s nice to have a succinct explanation for this aspect of digestion.

(Christy Hemphill) #4

It was interesting what they said about resistant starch too. I love potatoes and they have such a bad rap nowadays. Some people say you might as well just eat a donut. But I had read before that the glycemic index of potatoes changes quite a bit if you cool them and reheat them, which is what I usually do when I eat potatoes, because I bake up a batch of them and then reheat them (topped with black beans and avocado, mmm). I guess it has to do with those starches crystallizing, which is what makes reheated or cold potatoes good food for your microbes.

(Phil) #5

Fairly recent review of probiotics from an infectious disease perspective:

(Mervin Bitikofer) #6

I too am in rebellion against the whole “potato = nothin’ but starch” fad - probably because I love just about everything potato-ey or starchy (so yes, deep confirmation bias at work here.) But even if a potato were “only starch” at least it’s a complex carbohydrate, and so still a step above all the simple sugars being downed in cola beverages. But the potato does come with a smattering of other nutrients. I even heard somewhere (need to verify this - so it’s just hearsay for the moment) that Americans get more vitamin C from potatoes than they do any other source - presumably not because the potatoes have so much of it, but just because we eat so much of them (in the form of french fries probably). So it’s a little difficult to take people seriously calling a baked potato junk food if they haven’t been trashing the soft drink industry even more. I do get it - so many need to lose weight, so excessive carbs may indeed be an enemy. But that makes for a target-rich environment around here. Blaming the potato is probably more like blaming our obesity problem on excessive carrot consumption. Yes - it has carbs. But it’s so far down the list of your biggest enemies that very few need “waist” time worrying about that one!

(Christy Hemphill) #7

Two of my children are “underweight” and the other one is borderline. I think it is just genetic, since their father (who weighs ten pounds more than me and is several inches little taller) easily eats two or three times as many calories as I do in a day and does not gain weight. So much nutrition advice is geared toward avoiding obesity, and I am always saying, “Here, kid, have a third slice of bread…sure, put some more butter on it…”

(Chris) #8

From memory I think the latest advice is to eat not just more fibre but also a broader range to encourage a broader range of gut microbes. Probiotic supplements could have the effect of flooding the system with a narrow range of bugs.

Hmmm. I must make another batch of sauerkraut. Fibre and healthy microbes in one.

(Christy Hemphill) #9

Yes, that is what this article said. Lots of fiber, lots of variety.

(Phil) #10

No doubt the fiber is important and helpful. The probiotics, not so well supported. Little evidence exists that they provide benefit in most situations, as you would expect when the bacteria in them are not normal inhabitants of the GI tract. Certainly there may be some situations of benefit, but even then the evidence is scant. In any case, most probiotic sales are for situations where there is no detectable benefit.

(Robin) #11


That is a good one.

Baby steps…think positive. The switch to Fritos was a baby step…

(Robin) #12

Interesting article. And yes I agree that fermented Auks does not sound at all interesting. I also wondered – and maybe “Dr Phil” here would have a thought – if it would be hard for a non-fiber eating modern to suddenly start eating the 100 daily grams of fiber that we think our ancestors ate??? Would this amount of fiber consumption be something we had to get our digestive systems accustomed to seeing ? Actually, most of us do not keep track of daily consumption but 100 sounds like a lot.

(Phil) #13

Ha! Reminds me of an old SNL skit about a cereal named “Colon Blow” , so it could cause problems. Gas produced by colon fermentation certainly happens.
On a practical basis, I often tell folks that the methylcellulose fiber supplements cause less gas than the others, as they are not as easily digested by colon bacteria.
Going back to the original post, there was a link in the article I posted that was interesting:

(Robin) #14

Colon Blow ---- quite a visual while I am eating breakfast. Thanks!!! (LOL)

Gas is produced by colon fermentation? Never thought of it that way…

(Phil) #15

Most colon gas is produced in the colon ( a little bit is swallowed air, but usually a minor portion.) Fiber (and other nutrients also) is generally not digested and absorbed, and when it hits the colon, the bacteria feast on it and methane is a byproduct. The fiber also absorbs water and that and the osmotic action of the breakdown products soften the stool, and decrease transit time, which may decrease the exposure to carcinogens, so is good in many respects, though the source of hilarity for middle school boys.

(Robin) #16

“Decrease transit time”…never quite heard it put that way…would love to ask more, but who knows how many “middle school boys” read this blog??

(Phil) #17

Ha! There is a lot of jargon in medicine (and other fields) that indeed do sound strange when uttered outside the confines of the field. But that term aptly serves to describe how moving potential carcinogens ( like the BBQ I had for lunch) through the GI tract more quickly possibly decreases their effect.

(Robin) #18

And WHY exactly are they called “potential carcinogens” — my apologies to BBQ eaters everywhere…are MOST foods potential carcinogens??? P.S. This is the sort of conversation BioLogos gets when they title a blog “Eat more fiber, feed your microbes…” Most of us only saw and reacted to the first three words since we never see our microbes… and and think our mothers whispered some idea in your ears at BioLogos

(Phil) #19

Life is pretty carcinogenic in general, but some foods have been implicated more than others. The brown charring with grilling and smoking meat is one of them, along with many, many others. In fact, if they removed known natural carcinogens from the shelf, you would find a lot of empty shelves. However, the dose makes the poison in most cases, so don’t worry too much.

(Robin) #20

Good to know. BBQ does not show up on Weight Watchers diet list too often anyway…but perhaps it does for some people. But probiotics – aka food, as you put it – do…Thanks again, and good discussion…I found Christy’s ideas of what to do with potatoes interesting — the idea of changing glycemic index by cool then reheat…never have looked into that…