Perhaps one of the fastest-growing fields in the bioscience world, the microbiota continues to be heavily researched, and with amazing and very wide-ranging findings.
For example, did you know that the gut microbiota has an influential role in osteoarthritis? In a review, authors summarized research that cumulatively presented evidence supporting the concept of a gut-joint-axis, where in there is an interaction between the gut microbiota and factors of OA development, leading to the idea of promising manipulation of the gut microbiota to manage OA when risk factors emerge. They write, “To date, some lines of evidence indicate that gut microbiota interventions may be realized through probiotics, prebiotics, nutraceuticals, exercise,” among others.
The gut microbiota also appears to have an effect on blood pressure, according to new research, based on emerging evidence suggesting that dysbiosis can have negative impact on blood pressure; previous murine research has shown that the gut microbiota composition in hypertensive subjects was different than those with normal blood pressure. When gut bacteria was transferred from hypertensive subjects into normal BP subjects, those normal BP subjects developed hypertension.
This new study sought to define how the gut microbiota impacted blood pressure – and found, for the first time, that intermittent fasting reshaped the composition of the gut microbiota in subjects, and that these changes appeared to have positive effects in blood pressure normalization. They write, “Fasting schedules could one day help regulate the activity of gut microbial populations to naturally provide health benefits."
Yet another link between health and the microbiota was found. According to researchers in a new study, autism spectrum disorder is related to changes in the gut microbiome. "We were able to see that within an individual, changes in the microbiome were associated with changes in behavior," they write.
The researchers compared the gut microbiome composition between individuals with autism spectrum disorder and neurotypical controls and found that gastrointestinal symptoms were significantly higher in those with autism compared with those without autism, and that gut microbiome composition was significantly associated with autism. The researchers asserted that this further supports the fact that the gut microbiome could be a valuable therapeutic target for children with autism spectrum disorders.
The microbiota also takes years to mature and is vastly different between cesarean-born babies and those born vaginally. A research team has previously demonstrated that the composition of children's intestinal microbiota is affected by their mode of delivery and diet. In their new study, the researchers examined in detail how the composition of intestinal bacteria in 471 children born at a hospital had developed. They took fecal samples at newborn, and then at ages 4 months, 12 months, 3 years and 5 years.
The team found that the intestinal microbiota takes several years to mature as even at age 5, this ecosystem is incomplete. Also, at 4 months of age, the gut microbiota in the cesarean-born infants was less diverse compared with vaginally born infants. However, when the children were 3 and 5 years the microbiota diversity and composition had caught up and were largely normalized intestinal microbiota.
"Our findings show that the gut microbiota is a dynamic organ” they write. "It's striking that even at the age of 5 years, several of the bacteria that are important components of the intestinal microbiota in adults are missing in the children.”
On the other end of the (life) spectrum, researchers believe that a type of gut microbiota profile may predict mortality of the host. This large population study (of 7,000 adults) examined the connection between human gut microbiota and health and mortality from samples collected in 2002 and followed up until 2017. They discovered that a large amount of enterobacteria in the gut microbiota is related to long-term mortality risk in adult population.
The researchers stated, "Many bacterial strains that are known to be harmful were among the enterobacteria predicting mortality, and our lifestyle choices can have an impact on their amount in the gut. By studying the composition of the gut microbiota, we could improve mortality prediction. The data used in this research make it possible for the first time to study the long-term health impact of the human gut microbiota on a population level.”
The microbiota is also giving up secrets about brain activity as well as mental health. For example, a recent study confirmed that there is a link between Alzheimer’s disease development and the contents and/or profile of the gut microbiota, which has been shown to influence the development of amyloid plaques in the brain. Amyloid plaques are characteristic of the development of Alzheimer’s.
The researchers explained that they have previously shown that the gut microbiota composition in individuals with Alzheimer’s was altered distinctly from those with normal brain structure, and that they had significantly reduced microbial diversity along with an overrepresentation of some bacteria and underrepresentation of others. Here they wanted to find out if inflammation in the blood is a mediator between the microbiota and the brain in 89 elderly individuals aged 65 to 85.
"Our results are indisputable: certain bacterial products of the intestinal microbiota are correlated with the quantity of amyloid plaques in the brain,” they stated. “Indeed, high blood levels of lipopolysaccharides and certain short-chain fatty acids (acetate and valerate) were associated with both large amyloid deposits in the brain.” Conversely, higher levels of butyrate, were associated with fewer amyloid plaques.
The gut microbiota was also found to impact mood regulation and brain function in a new study. The researchers found that an imbalance in gut bacteria (dysbiosis) can cause a reduction in some metabolites, resulting in depressive-like behaviors. These findings show that a healthy gut microbiota contributes to normal brain function.
They discovered that when dysbiosis exists, “some lipid metabolites [endocannabinoids] that are vital for brain function disappear, encouraging the emergence of depressive-like behaviors. In this particular case, the use of specific bacteria could be a promising method for restoring a healthy microbiota and treating mood disorders more effectively.”
The microbiota composition can even illustrate bone health status. One study showed that bone density is linked to alteration in the gut microbiota composition that is triggered by heat. In the murine study, the researchers transplanted the microbiota of subjects living in a warm environment to those with low bone density and found that post-transfer, the low-bone-density subjects showed a reversal, in which their bones became stronger and denser.
The influence of the gut microbiota on health and specific conditions continues to be revealed as well as validated, substantiating the value of incorporating dietary probiotics into daily wellness habits. Ensuring a healthy, viable gut microbiota may be the key to healthy longevity!