Highlights:

  • The centenarians of Guangxi, China have increased diversity within their gut microbiota as compared to younger elderly people.
  • A probiotic complex made of two strains of bacteria found in the Guangxi centenarians led to benefits in naturally aging mice, including greater mobility and decreased anxiety.
  • The treated naturally-aged mice also had decreased oxidative stress, increased antioxidant activity, and decreased inflammation.

Longevity and the gut microbiome – the bacteria within the intestines – are thought to be tightly linked, however identifying the important core bacteria for longevity is proving to be a challenge. A recent study which looks at the long-lived population in Guangxi, China is trying to do just that. 

The study, out of China and published in Nutrients, looks at the aging population of Guangxi, a region of China with a large population of centenarians. The scientists looked at over a hundred fecal samples to identify gut microbiota important for healthy longevity. By analyzing bacterial ribosomal RNA – the instructional code that helps to stitch together protein building blocks –from the Guangxi population, Li and colleagues uncovered two bacterial strains that could potentially be used as a longevity intervention. These two strains were given to naturally aging mice and shifted the mice gut microbiota toward a healthy longevity state. Additionally, the probiotics – healthy bacteria intended to benefit the body when consumed – helped to improve their antioxidant capabilities and reduce inflammation. Furthermore, the mice had reduced anxiety and reduced brain aging when given the probiotics.

“These results may also provide an important theoretical reference for the healthification of the intestinal microflora in the general population, and even the remodeling of the structure of the longevity-state intestinal microflora,” the scientists wrote.

Longevity Bacteria Found in Centenarians May Influence Healthspan

The scientists divided the participants from the Guangxi area into two groups: those 90 years or older (LG group) and those less than 90 years old (YG group). They found that the LG group had increased diversity within their intestinal microbiome, with decreased ratios between the two largest families of bacteria in the gut – Firmicutes and Bacteroides –, as compared to the YG group. 

Li and colleagues isolated bacteria from the feces of centenarians and found that B. fragilis – one of the Bacteroides and previously shown to improve heart function in rats – is particularly abundant in the centenarians and may influence healthy longevity through its effects on inflammation. Lactobacillus – part of the Firmicute family –was also particularly abundant in the centenarians and has been shown to help build antioxidant systems and reduce inflammation, promoting long, healthy lives. Further analysis showed that combining these two probiotics may make a probiotic complex that could benefit natural aging. 

Probiotic Complex from Centenarians Increases Healthspan in Natural Aging

Li and colleagues treated 20-month old mice (about 64 in human years) with the Lactobacillus fermentum LTP1332 and Bacteroides fragilis LTBF12 probiotic complex for six weeks. Following treatment, the naturally aging mice had shinier hair, softer skin, and were more mobile, active, and curious – basically looking and acting like much younger mice. In an open field experiment – designed to assess the exploration of new environments, mobility, and anxiety of the mice – the probiotic group, particularly the high-dose group, passed through the experimental center over 50% more times, suggesting that their motor exploration ability was improved by the probiotics. Additionally, the total distance traveled was increased, and the number of times they groomed themselves – including face wiping, scratching and rubbing of the head area including ears, and cleaning of the entire body – decreased in the probiotic-treated group, indicating increased motor abilities and decreased anxiety, respectively. Furthermore, the treated mice exhibited a broader range of movement than the control mice.

Effect of Probiotics on Motor Abilities and Anxiety in Aging Mice: High Dose (Red - H) shows Increased Total Movement (B), Decreased Upright Hind Legs (C), and Decreased Combing Times (D), compared to Untreated (Blue - C) and Low Dose (Green - L) Mice
(Li et al., 2023 | Nutrients) Probiotics Increase Motor Abilities and Decrease Anxiety When naturally aging mice were given high doses of probiotics (red – H), they had increased total movement in an open-field test (B), decreased times on upright hind legs (C), and decreased number of combing times (D) – indicating increased movement and decreased anxiety – as compared to both untreated mice (blue – C) and mice treated with low doses of probiotics (green – L).

Research shows that the brain and gut are tightly linked, with evidence that inflammation and irritation in the intestines can lead to effects on mood and vis versa. Bacteria in the gut have been shown to send signals to the brain via the gut-brain axis. The scientists found here that probiotic treatment – which influences the gut microbiome – also had beneficial effects on the brains of naturally aged mice, specifically the hippocampus -the brain region directly involved in learning and memory processes. 

The treated mice had healthier cells within their hippocampi, as well as increased antioxidant activity and decreased inflammation and oxidative stress, both of which have been repeatedly shown  to contribute to the aging process. Furthermore, the probiotic treatments led to the make-up of the gut microbiota becoming more similar to the long-lived people from the Guangxi region.

Effect of Probiotics on Oxidative Stress and Inflammation in Aging Mice: High Dose (Red - H) shows Decreased Brain Oxidative Stress (D) based on MDA measurements and Increased T-SOD (E) Antioxidant Protein, compared to Untreated (Blue - C) and Low Dose (Green - L) Mice
(Li et al., 2023 | Nutrients) Probiotics Decrease Oxidative Stress and Inflammation When naturally aging mice were given high doses of probiotics (red – H), they had decreased oxidative stress in their brains (D) – based on MDA measurements typically used to look at oxidation – and increased T-SOD (E), an antioxidant protein used to scavenge reactive molecules and prevent further damage, as compared to both untreated mice (blue – C) and mice treated with low doses of probiotics (green – L). 

Probiotics for Increased Healthspan

Many studies have illustrated that long-lived individuals have a different gut microbiome composition than those who are not as long-lived, suggesting the gut microbiome plays a role in healthy longevity. Here, Li and colleagues show that a complex of probiotics – isolated from long-lived individuals in the Guangxi region of China – leads to health benefits in naturally aging mice, which may help extend their longevity. 

Multiple studies have shown that probiotics may be a great anti-aging therapy leading to longevity and increased healthspan. However, many of these studies have been done in mice or other organisms, and few long-term studies have looked at the effects of probiotics on human health. More research is needed before proclaiming probiotics to be a useful and effective anti-aging therapy, but most probiotics have minimal side effects and lots of benefits. As always, please speak with a healthcare provider before starting or stopping any supplements or medications.