This month’s Top Reads in health, nutrigenomics, and medicine updates was just released on my home page. Once again, the stars of media headlines were the microbial sweethearts that line our insides and make a home in our inner tubes.
These stories I thought deserved special attention. Below are the honorable mentions and my commentary on why these buggy friends of ours are so important for our health!
The Gut-Brain Connection
I’ve written in the past how the microbiota in our bellies can affect our moods. This occurs through various mechanisms which include their role in chemical signaling, neurotransmitter formation, nutritional absorption, nervous system feedback (through the vagal nerve and the guts’ very own enteric nervous system), inflammatory mediators, and more actions still to be discovered! 1-2
For instance, in a study in Behavioural Brain Research, researchers discussed the relationship between gut health and the brain via the microbial modulation of the neurotransmitter serotonin.3 (Note: serotonin may not directly affect your brain, there is controversy in this now, but it will have an impact on the nervous system and overall nervous tone.)
Another study in Neurogastroenterology & Motility further explained this concept through discussing a general and unique bacterial “fingerprint” of each individual in which the balance plays a role in gastrointestinal, neuroendocrine, and immune health. The authors write:
The ability of gut microbiota to communicate with the brain and thus modulate behavior is emerging as an exciting concept in health and disease. The enteric microbiota interacts with the host to form essential relationships that govern homeostasis. Despite the unique enteric bacterial fingerprint of each individual, there appears to be a certain balance that confers health benefits. It is, therefore, reasonable to note that a decrease in the desirable gastrointestinal bacteria will lead to deterioration in gastrointestinal, neuroendocrine or immune relationships and ultimately disease. 4
Finally, there was the 2013 article that went viral in the media on the results of a study in which women were given a fermented milk product enriched with probiotic strains. The authors reported:
Four-week intake of an FMPP (fermented milk product with probiotic) by healthy women affected activity of brain regions that control central processing of emotion and sensation.5
Recently, another news release from Health Day reported on support for a more direct connection of the gut-brain. Specifically, this was between those with inflammatory bowel disease and anxiety. The article states:
People with inflammatory bowel disease, such as Crohn’s disease or ulcerative colitis, have an increased risk for an anxiety disorder, especially women, a new study suggests.6
The Gut-Joint Connection
Making our way from the brain to the bones, a recent metagenonome-wide association study (MGWAS) of fecal, dental, and salivary samples from rheumatoid arthritis (RA) patients and healthy controls was completed. The researchers discovered that there was a concordance between the gut and oral microbiomes of rheumatoid arthritis (RA) patients and healthy
controls. Specifically, the authors found dysbiosis (microbial imbalance) in the gut and oral microbiomes of RA patients. This imbalance was partially resolved with treatment and distinguished those with RA from healthy controls.
According to the authors, “In particular, Haemophilus spp. were depleted in individuals with RA at all three sites and negatively correlated with levels of serum autoantibodies, whereas
Lactobacillus salivarius was over-represented in individuals with RA at all three sites and was present in increased amounts in cases of very active RA.”7
The authors continued on to explain how these imbalances in the gut microbiota can negatively impact the body via oxidative stress and alterations in nutrients. Furthermore, the unwelcome critters caused a case of “mistaken identity” in the RA patients. This means that the body attacked its own joints, a mechanism linked to autoimmuinty.7
It’s yet to be determined if the alterations were related to a pathological response or a protective response. For instance, L. salivarius, which was overrepresented, has been shown to produce unmodified bacteriocins. These substances may “directly inhibit the invasion of competing strains or pathogens, or modulate the composition of the microbiota and influence the host immune system.” 8
In non-geek terms, it means that these little guys could have been in abundance as a protective mechanism to make more harmful bad critters unwelcome. When their job was done, and the bad guys went away, they “we’re outta there!”
The Vagiome-Birth Connection
Finally, moving down farther in the body another study demonstrated that not only do our bugs affect our health now, the health of a mother’s vaginal bacterial blend can affect her birth outcomes. Health Day reports:
Researchers have come to learn how millions of germs carried in the body affect your health. Now, a new study links premature birth to a specific kind of bacterial blend in the vagina.
“Our discovery is important because it might allow us to determine which women are at elevated risk of premature birth by measuring the kinds of bacteria in their vagina early in pregnancy when there is still time to intervene and try to reduce the risk,” said study co-author Dr. David Relman, a professor of medicine at Stanford University in California.9
How we treat our microbiome has direct outcomes on our offspring and our own health outcomes. This means that feeding these critters right (think lots of yummy veggies), exercising, and decreasing our stress, can make them and us very happy.
Also, as long as the bugs aren’t inching up your small intestine (a condition called SIBO), you don’t want to forget to swallow your bugs!10
For more information on happier bugs, read these three simple steps to support your microbiome.
1. Crohn’s Disease, Colitis Tied to Anxiety in Study. Health Day. August 4, 2015.
2. Gut feelings: the emerging biology of gut-brain communication. Nature Reviews Neuroscience. August 2011. (12): 453-466. doi:10.1038/nrn3071
3. O’Mahonya AM, Clarkea G, Borrea YE, Dianan TG, Cryana JF. Serotonin, tryptophan metabolism and the brain-gut-microbiome axis. Behavioural Brain Research. 277(15): 32-48. January 15, 2015.
4. Cryan JF1, O’Mahony SM. The microbiome-gut-brain axis: from bowel to behavior. Neurogastroenterol Motil. 2011 Mar;23(3):187-92. doi:
5. Tillisch K, Labus J, Kilpatrick L, Zhiguo J, Stains J, Ebrat, B, et al. Consumption of Fermented Milk Product With Probiotic Modulates Brain Activity. Gastroenterology. 2013; 144 (7): 1394-1401.
6. Crohn’s Disease, Colitis Tied to Anxiety in Study. Health Day. August 4, 2015.
7. The oral and gut microbiomes are perturbed in rheumatoid arthritis and partly normalized after treatment. Nat Med. 2015 Aug;21(8):895-905. doi: 10.1038/nm.3914.
8. Lactobacillus salivarius: Bacteriocin and probiotic activity. Food Microbiology. December 2013; 36(2):296-304.
9. Are Vaginal Germs Linked to Preemie Birth? Health Day. August 17, 2015.
10. A randomized controlled trial to test the effect of multispecies probiotics on cognitive reactivity to sad mood. Brain, Behavior, & Immunity. August 2015. (40): 258-264.