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New Genome Study of B. longum subsp. longum by Morinaga Milk May Explain the Species' Wide Distribution across All AgesBifidobacterium 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.1,2 Today, Morinaga Milk Industry Co., Ltd. (TOKYO:2264), a leading Japanese dairy product company, announced the results of a groundbreaking new genome study, in collaboration with the SFI Research Centre APC (News - Alert) Microbiome Ireland, that may explain why. This press release features multimedia. View the full release here: http://www.businesswire.com/news/home/20180214005461/en/ (Fig.1) Distribution of gut microbiota in healthy Japanese subjects (Graphic: Business Wire) 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.3
Study Overview 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 the SFI Research Centre APC Microbiome Ireland at the National University of Ireland, Cork, 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.
B. longum subsp. longum Strains Separated into Seven
Clusters No correlation was observed between isolated strains and subject age, although a significant negative correlation was found between the number of identified genes present in the strains and subject age. This suggests that B. longum subsp. longum strains isolated from younger subjects possess, on average, a higher number of genes compared to the ones from older subjects. Researchers performed further investigation to identify genes in each strain isolated from different age groups, and as a result, gene families were classified into four groups: infant, adult, elderly-predominant gene families, and genes that exhibit no relationship with subjects age (Fig.2).
Infant-associated Strains More Adapted to Utilize Carbohydrates
Found in Human Milk
Elderly-associated Strains More Adapted to Utilize Insoluble Fiber
Found in Vegetables In addition, two clusters of genes indicative of how bacteria respond to environmental stress were found in higher numbers among strains of B. longum subsp. longum isolated from elderly subjects, including the heat shock protein HSP20.5 Heat shock proteins are produced to help an organism respond to stress, such as extreme heat, oxygen exposure and starvation. It is reasonable to assume that strains with the ability to respond to stress are better able to adapt and survive.
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," stated Dr. Toshitaka Odamaki, Manager of Microbiota Research Dept. at Next Generation Science Institute of Morinaga and lead researcher of the study. "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," he added. "We assume this variety of genes and high transfer level of the bacterial species within families is the survival strategy of B. longum subsp. longum and is key to its wide distribution across the human lifespan," explained Dr. Odamaki. "This report could provide a promising foundation for future research aimed at identifying the best probiotic candidates at each key life stage," he continued. "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". Dr. Odamaki from Morinaga discussed these findings at the IPA World Congress + Probiota Barcelona held in Barcelona, Spain on February 7th -9th, 2018.
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View source version on businesswire.com: http://www.businesswire.com/news/home/20180214005461/en/ |