New Genome Study of a Bifidobacterium subspecies by Morinaga Milk and APC Microbiome Ireland May Explain its Wide Distribution Across All Ages
Bifidobacterium longum is one of only a handful of species of gut bacteria that is widely present among people of all ages, including infants, adults and the elderly. Recently, Morinaga Milk Industry Co., Ltd., a leading Japanese dairy product company, and APC Microbiome Ireland announced the results of a groundbreaking new genome study that may explain why.
The human gut is colonized by a collection of microbes (microbiome) which play an integral role in human health, by helping us digest our food, produce certain vitamins, regulate our immune system, and protect us against pathogenic bacteria. This current study revealed that one bacterial species, B. longum subsp. longum, demonstrates a wide variation in its genes that increases its competitiveness in the gut environment, because its genome adapts to the changing diet of each generation. In addition, it suggests that B. longum subsp. longum is extensively transmitted between relatives, and that such transmission does not occur only between mothers and infants, as previously believed, but also between other family members and even across three generations.
For the study, a total of 453 fecal samples were collected from healthy Japanese subjects aged 0 to 104 years, as a means of measuring the bacterial species present in the gut. In total, 871 different bacterial species were detected but only three species (Blautia wexlerae,Streptococcus salivarius and Bifidobacterium longum) were found to be present in more than 50% of the subjects across all generations. This finding highlights the broad distribution of B. longum across the human lifespan. In order to identify the mechanism that allows a specific species to be so ubiquitous, Morinaga, in collaboration with APC Microbiome Ireland, performed a comparative genome analysis on various strains of B. longum subsp. longum to determine genetic differences among strains isolated from people of varying ages.
The key finding were:
- B.longum subsp. longum strains separated into seven clusters
- Infant-associated strains more adapted to use carbohydrates found in human breast milk
- Elderly-associated strains more adapted to use insoluble fibre found in vegetables and respond to stress
- Certain strains have been transmitted between father and child, husband and wife, and even across three generations
“It is a remarkable finding that not only was transmission between mother and child observed, but also between father and child and even between husband and wife. This is also the first report of a particular strain of gut microbiota that appears to have been transmitted across three generations in a family, for instance, between a grandmother, mother, and infant”, stated Dr. Toshitaka Odamaki, Manager of Microbiota Research Dept. at Next Generation Science Institute of Morinaga and lead researcher of the study.
“APC Microbiome Ireland is very interested in how the human microbiota changes over the life stages, in response to exposure to different environmental factors such as habitual diet, antibiotic exposure, and levels of stress”, said Prof Douwe van Sinderen, project leader at APC Microbiome Ireland. He furthermore emphasized the attraction of such a joint scientific effort: “This was a particularly fruitful and gratifying collaborative project with an industry partner, Morinaga, because we were able to join our complementary skills and know-how allowing us to generate insights that we would otherwise not have been able to obtain on our own”.
These findings were published in the journal Scientific Reports.
Genomic diversity and distribution of Bifidobacterium longum subsp. longum across the human lifespan
Scientific Reports 2018; 8: 85 doi 10.1038/s41598-017-18391-x; T. Odamaki , F Bottacini, K. Kato, K.Yoshida, A. Horigome, J.z.Xiao and D.van Sinderen