Can we harness gut bacteria to fight heart disease and aging?

First, the researchers looked at a cohort of 10,207 Chinese participants, collecting information on 21 metabolic parameters to classify individuals into five “metabolic multimorbidity clusters” clusters. These were:

They then looked at the impact of being in one of these clusters on overall cardiovascular disease risk over an average follow-up of 11.1 years.

They discovered that people in the obesity and hyperglycemia clusters were 75% and 117%, respectively, more likely to develop cardiovascular disease when compared to the healthy cluster.

The MC1, MC2, and MC3 clusters were all linked to “healthy” parameters, while MC4 and MC5 were associated with “unhealthy” parameters. These results were then validated in a cohort of 9,061 individuals, with a 10-year follow-up.

Researchers then looked at the gut microbiome of 4,491 participants from the original cohort, and sequenced the genomes of the microbes found there, to identify the presence and abundance of particular species.

They discovered that the microbiomes of people they assigned to the metabolic multimorbidity clusters had certain overlapping characteristics.

They also characterized the species that were found in the microbiome of younger people and older people. They then plotted the presence of 55 age-related microbial species against age to develop a gut microbial age metric, which they then validated using existing cross-sectional data from Israel, the Netherlands, France, Germany and the United Kingdom and United States.

The microbiomes of younger people were associated with lower levels of Bacteroides species and older people had higher levels of Prevotella and Enterobacteriaceae species.

The study authors also pointed at microbial variation between individuals in different countries, and stated this could be an area for further research.

Further analysis showed that a younger microbial age was associated with lower cardiovascular disease risk.

The authors have argued this could mean the microbiome could be a target for cardiovascular disease prevention in older adults who are not metabolically healthy.

Catherine Rall, RDN, a registered dietitian based in Denver, CO, and certified nutritionist at Happy V, who was not involved in the research, told Medical News Today that:

“The results of this study show a strong correlation between poor gut microbiome health and an increased risk of morbidity-related conditions like cardiovascular issues. This suggests that a healthy gut microbiome can help to limit the impacts of aging on the body, becoming even more important in helping people stay healthy as they age.“

“While there is some merit to the idea that microbiome health can correlate effectively with someone’s biological age, our gut microbiomes are also highly changeable through prebiotic and probiotic supplementation and potentially even more extreme measures like fecal transplantation,“ she noted.

“I wouldn’t say that this represents our ability to reverse aging, but it can definitely help to improve health outcomes in people as they age,” said Rall.

The findings of this research are backed up by evidence from other studies, which have shown that gut dysbiosis — imbalance of bacterial populations in the gut — is associated with a range of inflammatory conditions, including inflammatory bowel disease (IBD), rheumatoid arthritis, and systemic lupus erythematous, but also cardiovascular disease.

There are also links between those conditions, including IBD, and cardiovascular disease.

The authors of this study looked at heart attack, stroke, and death related to cardiovascular events, but other studies have linked gut dysbiosis to a range of cardiovascular risk factors, including atherosclerosis, hypertension, heart failure, chronic kidney disease, obesity, and type 2 diabetes.

However, the core question remains: Does dysbiosis cause these problems or do these conditions cause dysbiosis?