Dr. Lamm's weekly review of relevant articles and research

There is an increasing amount of information available about the gut.  Here are a few informative articles you may find valuable.

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Exercise Boosts Gut Microbiome Diversity

Exercise Boosts Gut Microbiome Diversity

Published: Jun 9, 2014, By Kristina Fiore, Staff Writer, MedPage Today, Reviewed by Robert Jasmer, MD; Associate Clinical Professor of Medicine, University of California, San Francisco

Being physically fit appears to boost the diversity of gut bugs, researchers found.

In a case-control study, Irish athletes had a far wider range of intestinal microbes than did matched controls who weren't athletes, Fergus Shanahan, MD, of the University College Cork in Ireland, and colleagues reported online in Gut.

"Exercise seems to be another important factor in the relationship between the microbiota, host immunity, and host metabolism, with diet playing an important role," they wrote.

There's been much attention surrounding gut microbiota and its relationship with obesity and metabolism, but few have looked specifically at the effects of exercise on these gut microbes.

Shanahan and colleagues looked at 40 professional athletes from an international rugby team while they participated in pre-season camp -- a regulated environment -- and compared them with healthy male controls from the Cork region of Ireland.

They found that athletes and controls differed with respect to plasma creatinine kinase, a marker of extreme exercise, and inflammatory and metabolic markers. Athletes had less inflammation and better metabolism than did controls, they reported.

Athletes also had a far higher diversity of gut bugs -- 22 phyla, 68 families, and 113 genera compared with just 11 phyla, 33 families and 65 genera for controls with a low body mass index (BMI), and 9 phyla, 33 families and 61 genera for controls with a high BMI.

Athletes also consumed far more protein than controls, with protein accounting for 22% of their total energy intake compared with 16% of energy intake for low-BMI controls and 15% for high-BMI controls.

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The Environment Within: Exploring the Role of the Gut Microbiome in Health and Disease

The Environment Within: Exploring the Role of the Gut Microbiome in Health and Disease
Lindsey Konkel, Jayne Danska, Sarkis Mazmanian, Lisa Chadwick, Environ Health Perspect. 2013;121(9):a276-a281.

Introduction
The human genome codes for approximately 23,000 genes, [1] yet some experts have suggested that the total information coded by the human genome alone is not enough to carry out all of the body's biological functions. [2] A growing number of studies suggest that part of what determines how the human body functions may be not only our own genes, but also the genes of the trillions of microorganisms that reside on and in our bodies.

The genomes of the bacteria and viruses of the human gut alone are thought to encode 3.3 million genes. [3] "The genetic richness and complexity of the bugs we carry is much richer than our own," says Jayne Danska, an immunologist at the Hospital for Sick Children Research Institute in Ontario, Canada. "They serve as a buffer and interpreter of our environment. We are chimeric organisms."

A role for gut microbes in gastrointestinal function has been well documented since researchers first described differences in the fecal bacteria of people with inflammatory bowel disease. [4] The molecular mechanisms responsible for the gut microbiome's impact on metabolism and diseases throughout the body remain largely unknown. However, researchers are beginning to decipher how the microorganisms of the human intestinal tract influence biological functions beyond the gut and play a role in immunological, metabolic, and neurological diseases.

A New Normal
Early research on microbiota focused largely on the commensal bacteria that reside in the human gut. Commensal gut bacteria supply nutrients, help metabolize indigestible compounds, and defend against colonization by nonnative opportunistic pathogens.

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Belching: A Very Common Set of Symptoms

Belching: A Very Common Set of Symptoms

Dr. David Johnson, Professor of Medicine and Chief of Gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia. GI Common Concerns -- Computer Consult.

Today I want to talk about a very common set of symptoms that every one of us has experienced: belching, air swallowing, and hiccups.[1] We see these referrals from primary care. What do we do with these patients? From a gastroenterologist's perspective, what do these symptoms mean?

Let's start with the issue of belching (eructation).

It is not uncommon for patients to describe occasional belching; in fact, it is physiologic. However, there is a difference between a gastric belch -- the normal physiologic response -- and a supragastric belch.

The gastric belch means that the air in the stomach is vented through transient relaxations of the lower esophageal sphincter. The air comes up, the upper esophageal sphincter relaxes, and the air is vented physiologically, a process that occurs 20-25 times every day. It is a normal reflex response.

However, most people who complain of excessive belching don't have gastric belching. They have supragastric belching, meaning that the source of air in the esophagus is not swallowed air; instead, it is transported in, and then by retrograde propulsion, it is driven back out into the pharynx and eructation occurs.

With esophageal impedance manometry, we are able to define this process much more clearly. We can tell when someone volitionally swallows air. We can see the changes in esophageal peristalsis with a volitional swallow.

In the case of supragastric belching, air is drawn back into the esophagus by a diaphragmatic contraction, which creates negative intrathoracic pressure. Thus, the air is sucked into the esophagus and expelled back out, without being swallowed. This is what occurs in most people who have supragastric belching.

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