Gut | Molecularist

Host response: Probiotic ingestion alters mood : Nature Reviews Microbiology

“There is growing evidence that the intestinal microbiota interacts with the host central nervous system (CNS) to modify stress responses and anxiety behaviour; this is the so-called gut–brain axis. Bravo et al.Lactobacillus rhamnosus JB-1 can alter the transcript level for receptors of the neurotransmitter GABA (γ-aminobutyric acid) in the CNS in a region-dependent manner.”

Yet one more data point on the bugs-gut story.

[This is not an open access article. Boo. Hiss.]

Read this article…

PLoS ONE: Barcoded Pyrosequencing Reveals That Consumption of Galactooligosaccharides Results in a Highly Specific Bifidogenic Response in Humans

“Prebiotics are selectively fermented ingredients that allow specific changes in the gastrointestinal microbiota that confer health benefits to the host. However, the effects of prebiotics on the human gut microbiota are incomplete as most studies have relied on methods that fail to cover the breadth of the bacterial community. The goal of this research was to use high throughput multiplex community sequencing of 16S rDNA tags to gain a community wide perspective of the impact of prebiotic galactooligosaccharide (GOS) on the fecal microbiota of healthy human subjects.”

I’ve seen a ton of papers on “probiotics”, but I think this is the first I’ve heard of “prebiotics”. There is mounting data about the effect of gut bugs on our own systems, and there is a growing set of data on how our diet affects our gut bugs. A wee Google search shows that there’s been a lot of papers data on specific foods that selectively promote the growth of specific gut bugs.

Hm, this is really interesting. It all seems to be coming together. My suggestion: if you’re a grad student or a post-doc in biology, human gut microbiology and ecology is gonna be a big topic in the near future. It’s gonna change the face of medicine.

Read this article…

Your Gut Bacteria Are What You Eat – ScienceNOW

“A large European-Asian consortium brought some order to the chaos when it reported in a Nature paper in April that humanity can be roughly divided into three “enterotypes” depending on which genus of bacteria dominates in people’s gut: Bacteroides, Ruminococcus, or Prevotella. People’s enterotype appeared to be stable over time, but it remains unclear why your gut population might be so radically different from your neighbor’s.”

Yet another report on diet and gut microbiome. If I could start all over again in grad-school, I’d study this. Human microbiological ecology is going to be big in so many areas, helping us understand the effects that our microbiome has on our health. And of course, this will go hand-in-hand with practical use of naturally occurring microbes.

Read this article…

Predicting a Human Gut Microbiota’s Response to Diet in Gnotobiotic Mice

“A model community of 10 sequenced human gut bacteria was introduced into gnotobiotic mice, and changes in species abundance and microbial gene expression were measured in response to randomized perturbations of four defined ingredients in the host diet. From the responses, we developed a statistical model that predicted over 60% of the variation in species abundance evoked by diet perturbations, and we were able to identify which factors in the diet best explained changes seen for each community member. The approach is generally applicable, as shown by a follow-up study involving diets containing various mixtures of pureed human baby foods.”

Another great report I can’t read at the moment (no subscription). This sounds like a nice analysis of something everyone has been seeing. Looking to see effect of other diets, beyond the baby food tested.

Read this article…

Gut bacteria in Japanese people borrowed sushi-digesting genes from ocean bacteria | Discover Magazine

“Nori is, by far, the most likely source of bacteria with porphyran-digesting genes. It’s the only food that humans eat that contains any porphyrans and until recently, Japanese chefs didn’t cook nori before eating it. Any bacteria that lingered on the green fronds weren’t killed before they could mingle with gut bacteria like B.plebius. Ruth Ley, who works on microbiomes, says, “People have been saying that gut microbes can pick up genes from environmental microbes but it’s never been demonstrated as beautifully as in this paper.””

Japanese gut bacteria picking up genes from marine bacteria that live on seaweed. This blew my mind, but I am not surprised. We do know that there can be rapid gene changes in humans (ADH, lactase), why shouldn’t there be rapid changes in our fellow microbiomes? Very interesting implications with respect to therapy and diets.

Read this article…

Divided by language, united by gut bacteria – people have three common gut types | Discover Magazine

“Enterotypes aren’t quite as well-defined as, say, blood groups, but they could have similar uses as medical markers. The microbiome helps us to digest our food and it affects our susceptibility to diseases; the enterotypes could reflect these roles. Each enterotype was dominated by a specific genus of bacteria, and varied in the proportions of the other members. They produce energy in subtly different ways, they’re particularly efficient at breaking down different nutrients, and they specialise at creating different vitamins.”

This article reports on findings that there are “enterotypes”. While I have been seeing slightly different findings from others, this just goes to show that we keep finding out new things about our bacteria.

One other thing: at the end of this article is a very interesting slide show with snippets of other interesting findings related to our microbiome. Do flip through it.

[via @changeist]

Read this article…

Going Viral: Exploring the Role Of Viruses in Our Bodies

“Many of the viruses prey on the bacteria in our bodies, altering their numbers and diversity and shuffling genes—including genes for antibiotic resistance—from one bacterium to another. At the International Human Microbiome Congress earlier this month, one provocative, albeit preliminary, finding emerged: Infants with unexplained fevers harbor many more viruses than healthy infants.”

Really nice news focus on the balance between the human virome and microbiome and what it means for us humans stuck in the middle. [Alas, the article is behind a subscription - Open Access Fail].

Bookmarked in Delicious.

Read this article…

Microbes Give Mice Intestinal Fortitude – ScienceNOW

"The findings add to the growing understanding of the complex relationship between our health and the bacteria living in and on our bodies. They also add to the growing conviction that it might one day be possible to curb diarrhea, and prevent other diseases, by making sure our guts have the right complement of bacteria."

I saw a Nature paper on how <a href="http://www.nature.com/nature/journal/v469/n7331/full/nature09646.html">Bifidobacteria can protect from enteropathogenic infection through production of acetate.</a> Both these papers suggest that there may be ways to control bacterial pathogenesis with other bacteria. Can you say probiotics?

Bookmarked in Delicious.

Read this article…

Molecularist

Host response: Probiotic ingestion alters mood : Nature Reviews Microbiology

PLoS ONE: Barcoded Pyrosequencing Reveals That Consumption of Galactooligosaccharides Results in a Highly Specific Bifidogenic Response in Humans

Your Gut Bacteria Are What You Eat – ScienceNOW

Predicting a Human Gut Microbiota’s Response to Diet in Gnotobiotic Mice

Gut bacteria in Japanese people borrowed sushi-digesting genes from ocean bacteria | Discover Magazine

Divided by language, united by gut bacteria – people have three common gut types | Discover Magazine

Going Viral: Exploring the Role Of Viruses in Our Bodies

Microbes Give Mice Intestinal Fortitude – ScienceNOW

Seek and ye shall find

Recent posts

Seek and ye shall find

Recent posts

Tags