The largest study of all time on the human gut has been underway since 2012 and they are discovering some remarkable things.

Scientists have been collecting fecal samples from around the world and tirelessly analyzing and comparing samples. Believe it or not, people have been paying $99 each to send their own stool samples along with oral and skin samples of bacteria to the research scientists. They also answer questions including those about their diet and lifestyle.

Three PhDs, Rob Knight, Jeff Leach, and Jack Gilbert founded the American Gut Project in 2012 on a quest to discover more about the human microbiome, more commonly referred to as ‘the gut’.

The microbiome is essentially a diverse world of different kinds of bacteria that live within our digestive system. These bacteria, some beneficial, some villainous, form a microscopic world of activity that can either fight disease, or give it the perfect atmosphere to thrive.

Many health problems have been linked to certain types of bacteria that live in our microbiome that are either foreign invaders or simply types that overgrow their beneficial bacterial counterpart and ruin the natural healthy balance.

So Far the American Gut Project Has Made the Following Discoveries

Firstly, they have noted that people who eat a wider variety of plants have a wider variety of bacteria in their microbiome. They haven’t necessarily stated that it’s better to have a more complex microbiome but they have noted that those people eating extra plants have less antibiotic resistance, which is noteworthy for sure.

This lack of antibiotic resistance could simply have to do with the subjects who favor a wide variety of plants eating fewer packaged and processed foods that contain animals raised with antibiotics.

The scientists have also discovered that people who have similar bacterial profiles tend to suffer from the same health problems. This was determined by matching subjects to controls with the same age, gender, and body mass index that did not suffer from the ailment.

Gut Bacteria and Mental Health

Some of the health problems that were found to have subjects in common with similar bacterial profiles were mental health problems, take PTSD for instance. Post-traumatic stress disorder (PTSD), schizophrenia, depression, or bipolar disorder have stood out in the study thus far as having a very strong link to gut bacteria diversity.

In other words, subjects who suffer from PTSD tend to have the same bacteria in their digestive tract. The same goes for depression and bipolar disorder.

When you consider how many mental and physical health symptoms are linked to nutritional deficiencies and also how vital a role our gut plays in absorbing and utilizing nutrients, this all starts to make a lot of sense.

Medical News Today puts it very well:

The results demonstrated that people who reported mental health issues had more bacteria in common with other people who reported similar problems than they did with the controls.

This association was strong regardless of gender, age, or geographical location. Also, the research suggests that some types of bacteria may be more prevalent in people who live with depression.

The MNT article also points out that a certain recent study found a connection between anxiety and a lack of healthy gut microbes. Another study discovered that certain bacteria are altered in people who suffer from PTSD.

“We observed a much greater microbial diversity than previous smaller studies found, and that suggests that if we look at more populations, we’ll see more diversity, which is important for defining the boundaries of the human microbiome,” said Daniel McDonald, PhD, the scientific director of the American Gut Project at UC San Diego School of Medicine.

The ultimate goal of the project is to map the human microbiome. Essentially it is to be able to tell people, ‘Alright, you’re suffering from this ailment, well here’s what is missing or different about your gut bacteria and here’s what you need to eat (or not eat) in order to fix it.’

Dr. Rob Knight said, “The human microbiome is complex, but the more samples we get, the sooner we will be able to unravel the many ways the microbiome is associated with various health and disease states.”