Example of a Bifidobacterium

Microscopic image of Bifidobacterium adolescentis. Magnification:1,000. © Y tambe

Japanese researchers have shown that a diet supplemented with a specific probiotic bacterial strain increases the lifespan of mice.

The mammalian gut is home to thousands of bacteria that contribute to food digestion and, in some cases, inflammatory gut disease. Beneficial bacterial species, known as probiotics, can enhance gut health by keeping the resident bacteria in check. Now, a team of researchers at the RIKEN Innovation Center have shown that feeding a specific strain of the probiotic Bifidobacterium animalis (subspecies lactis), to mice can lengthen their lifespan.

Mitsuharu Matsumoto and his colleagues previously showed that this strain, called LKM512, could reduce inflammation and alter the balance of intestinal bacteria in elderly humans, but its overall effect on lifespan was unknown. After feeding mice on a LKM512 diet supplement for 11 months, the researchers found that on average LKM512-treated mice lived longer, had fewer skin lesions, and had better hair quality than untreated mice.

Analyses of the gut of these mice revealed elevated gene expression in some bacterial species, indicating that LKM512 may improve gut health indirectly by regulating the levels of other gut bacteria. The probiotic treatment also prevented some age-related changes in bacterial composition of the gut, suggesting that it may protect the gut.

The gut lining acts as a barrier between the contents of the gut and the rest of the body, and damage can lead to infections or inflammatory diseases. The gut lining of LKM512-treated mice acted as a stronger barrier than the gut of control mice, due to increased levels of proteins that maintain tight connections between gut cells.

Increases in intestinal polyamine levels were also observed in LKM512-treated mice. Polyamines are organic compounds that reduce inflammation, and their levels tend to decrease with age. The observed polyamine increase did appear to reduce inflammation, as inflammatory markers in the blood and urine were lower in LKM512-treated mice compared with controls. “In future work, we hope to clarify the effectiveness of LKM512 in humans,” explains Matsumoto. If these findings extend to humans, inclusion of LKM512 into our diets could potentially improve overall health and lengthen our lifespan.

For further information contact:

Dr Mitsuharu Matsumoto
RIKEN Innovation Center, Japan
Email: m-matumoto@meito.co.jp