The Contrary H. Pylori

Angel&DevilTwo previous posts have led to a better acquaintance with the mysterious and confusing bacterium Helicobacter pylori, which turns out to be even more of an enigma than anyone suspected even a few short years ago. This member of the microbiome has many characteristics, and all of them seem to connect somehow with obesity, even if at a slight remove.

In the “connect the dots” game, H. pylori either definitely or probably links up with many things that also link up with obesity—diet, leaky gut syndrome, diabetes and the metabolic syndrome, inflammation, allergies, appetite, neurosteroid production, depression, antibiotics, the chronic inflammatory disease of asthma, autoimmune diseases, and mental/emotional health.

To paint with a broad brush, compare these two facts: American digestive tracts used to house much larger populations of H. pylori, but now their numbers are relatively small. Americans used to be much leaner, on average, but now obesity is an epidemic. So, there would seem to be a connection. More H. pylori correlates with less obesity, and more obesity correlates with less H. pylori.

But what about this? In present-day America, H. pylori is noteworthy for its prevalence in some ethnic groups. states:

The frequency of people infected may somehow be related to race. About 60% of Hispanics and about 54% of African Americans have detectable organisms as compared to about 20% to 29% of Anglo Americans.

By strange coincidence, Hispanic and African Americans are more prone to obesity and diabetes than those of European descent. Now, unlike two paragraphs ago, it looks like increased H. pylori correlates with increased obesity, and decreased H. pylori correlates with decreased obesity. Can two contradictory things both be true? In the microbiome, maybe. In that realm, two unstable dynamics, balance and synergy, are always in play, and our understanding is in its infancy.

Appetite and Eating

Previously we quoted a patient known only as Caroline, from the website, who studied up on all this because of her multiple allergies and a severe H. pylori infection, which fortunately was cured. Among the problems such an infection can cause, she names neurotransmitter imbalances:

You have probably heard of neurotransmitters so you know how important they are to the cells and brain. Serotonin will be off balance. OCD symptoms may be present and mood and appetite will be affected as well.

Yes, appetite, so there is another obesity link. Dr. Martin Blaser of New York University has studied H. pylori for decades, and found evidence that it influences production of a hunger-stimulating neurosteroid. Michael Pollan wrote:

Blaser’s lab has also found evidence that H. pylori plays an important role in human metabolism by regulating levels of the appetite hormone ghrelin. “When the stomach is empty, it produces a lot of ghrelin, the chemical signal to the brain to eat,” Blaser says. “Then, when it has had enough, the stomach shuts down ghrelin production, and the host feels satiated.” He says the disappearance of H. pylori may be contributing to obesity by muting these signals.

Other research hints that the bug might also regulate appetite by influencing production of the “satiety hormone” leptin, which would of course affect a person’s weight and body mass.

(To be continued…)

Your responses and feedback are welcome!

Source: “Helicobacter Pylori,”, 10/20/15
Source: “The real truth about H. pylori: allergies, autoimmune, & adrenal fatigue,”, 05/05/13
Source: “Some of My Best Friends Are Germs,”, 05/15/13
Source: “How Gut Bacteria Help Make Us Fat and Thin,”, 06/01/14
Image by Julia

Leave a Reply

Your email address will not be published.

FAQs and Media Requests: Click here…

Profiles: Kids Struggling with Weight

Profiles: Kids Struggling with Obesity top bottom

The Book

OVERWEIGHT: What Kids Say explores the obesity problem from the often-overlooked perspective of children struggling with being overweight.

About Dr. Robert A. Pretlow

Dr. Robert A. Pretlow is a pediatrician and childhood obesity specialist. He has been researching and spreading awareness on the childhood obesity epidemic in the US for more than a decade.
You can contact Dr. Pretlow at:


Dr. Pretlow’s invited presentation at the American Society of Animal Science 2020 Conference
What’s Causing Obesity in Companion Animals and What Can We Do About It

Dr. Pretlow’s invited presentation at the World Obesity Federation 2019 Conference:
Food/Eating Addiction and the Displacement Mechanism

Dr. Pretlow’s Multi-Center Clinical Trial Kick-off Speech 2018:
Obesity: Tackling the Root Cause

Dr. Pretlow’s 2017 Workshop on
Treatment of Obesity Using the Addiction Model

Dr. Pretlow’s invited presentation for
TEC and UNC 2016

Dr. Pretlow’s invited presentation at the 2015 Obesity Summit in London, UK.

Dr. Pretlow’s invited keynote at the 2014 European Childhood Obesity Group Congress in Salzburg, Austria.

Dr. Pretlow’s presentation at the 2013 European Congress on Obesity in Liverpool, UK.

Dr. Pretlow’s presentation at the 2011 International Conference on Childhood Obesity in Lisbon, Portugal.

Dr. Pretlow’s presentation at the 2010 Uniting Against Childhood Obesity Conference in Houston, TX.

Food & Health Resources