“While often-quoted figures suggest that the microbes that live in and on the human body outnumber human cells by 10:1, a more recent estimate suggests that we are essentially one part human to one part microbe in terms of cell number.3
These commensal microorganisms have a vital role in human health. They break down otherwise indigestible dietary fibres and other components of food, produce vitamins, promote the development and maturation of the immune system, and prevent pathogenic bacterial species from colonizing the gut.”
According to evidence cited in this paper, of the 1,000 or so gut bacteria we know of, any given individual will have around 160 different species of bacteria colonizing their gut. This individual combination is known as your gut microbiome, and can have a tremendous influence on health and well-being.
The diversity of your gut microbiome begins to be established when you are an infant, and is affected by genetics, whether you are breast or bottle fed, and your immediate environment. Later in life your microbiome is significantly affected by your food choices.4
Diets high in sugar and processed foods may reduce the diversity and your overall health, while diets high in whole foods high in fiber tend to have a beneficial impact.
For example, a number of studies have found obese individuals tend to have a less diverse gut microbiome,5 in addition to having greater numbers of certain harmful bacteria and fewer beneficial ones.
Studies have shown obesity is associated with as much as a 40% decrease in diversity,6 and that improving that diversity through probiotic supplementation can help resolve metabolic defects, resulting in fat loss.7
Obesity Associated With Frequent Diarrhea
“In the most comprehensive analysis of the relationship between Body Mass Index (BMI) and bowel habits to date, published today in Alimentary Pharmacology & Therapeutics, a team of physician-researchers at Beth Israel Deaconess Medical Center (BIDMC) found a strong association between obesity and chronic diarrhea independent of an individual's dietary, lifestyle, psychological factors or medical conditions …
‘While several previous studies have pointed to an association between obesity and bowel habits, all lacked data on whether dietary or other factors drive the connection,’ said corresponding author Sarah Ballou, Ph.D., a health psychologist in the Division of Gastroenterology, Hepatology, and Nutrition at BIDMC.
‘Our research confirms a positive association between obesity and chronic diarrhea and reveals for the first time that this relationship is not driven by confounding factors such as diet or physical activity level.’”
Looking at data from the 2009-2010 National Health and Nutrition Examination Survey, the researchers found 8.5% of obese and 11.5% of severely obese individuals reported chronic diarrhea, compared to 4.5% of those with normal weight. “Stepwise regression revealed that severe obesity was independently associated with increased risk of diarrhea,” the authors say.
Unfortunately, this study cannot shed light on why this is happening. One hypothesis is that chronic low-grade inflammation is at play. Not only is chronic inflammation a factor in obesity,10 but it can also contribute to diarrhea.
Systemic inflammation is also believed to be one of the leading triggers for other serious diseases, including neurological degeneration,11 Type 2 diabetes12and cardiovascular disease13 — all of which, by the way, are also associated with obesity.
Committing to making changes to your gut microbiome can do far more than improve your bowel habits. Your gut health is important to most aspects of your health, including reducing your risk for cancer, metabolic syndrome and depression.
Probiotics Shown to Alter Metabolism
Improving your microbiome can be as simple as increasing your intake of fermented foods or taking a quality protiotic supplement. Previous research has demonstrated that probiotics — beneficial bacteria found in fermented and cultured foods such as yogurt — have a measurable effect on your metabolism.
One such study,14 published in 2008, found the bacterial strains Lactobacillus paracasei and Lactobacillus rhamnosus affected a number of different metabolic pathways, including the metabolism of:
- Hepatic lipids
- Short-chain fatty acids (SCFAs)
As reported by Science Daily:15
“Adding 'friendly' bacteria changed the makeup of the bugs in the gut, not only because this increased the number of such bacteria, but also because the 'friendly' bacteria worked with other bacteria in the gut, amplifying their effects.
One of the many biochemical changes observed by the researchers was a change in how mice treated with probiotics metabolized bile acids. These acids are made by the liver and their primary function is to emulsify fats in the upper gut. If probiotics can influence the way in which bile acids are metabolized, this means they could change how much fat the body is able to absorb.”
While some claim taking probiotic supplements or eating fermented foods won’t have a significant impact on your microbiome, this particular study found otherwise. As noted by corresponding author Jeremy Nicholson with the department of biomolecular medicine at Imperial College:16
"Some argue that probiotics can't change your gut microflora — whilst there are at least a billion bacteria in a pot of yoghurt, there are a hundred trillion in the gut, so you're just whistling in the wind.
Our study shows that probiotics can have an effect and they interact with the local ecology and talk to other bacteria. We're still trying to understand what the changes they bring about might mean, in terms of overall health, but we have established that introducing 'friendly' bacteria can change the dynamics of the whole population of microbes in the gut."