A mother’s mouth may be the first source of placenta’s bacteria

For a long time, the womb was considered to be a perfectly sterile environment, but in the last few years several findings have revealed the fact that babies might first come in contact with microbes precisely in their mother’s womb.

The bacteria of a pregnant woman’s placenta are more similar to those of her mouth than those of any other part of her body. If bacteria travel from the mouth to the placenta, it’s possible that food that passes through a pregnant mother’s mouth may end up influencing the baby’s future microbiota and his/her health. These findings were published in the magazine Science Translational Medicine, by a team led by Kjersti Aagaard, of Baylor College of Medicine, Houston, and Texas Children’s Hospital.

The scientists collected samples of 320 placentas of women that had given birth. To avoid contamination by vaginal bacteria, samples were harvested under sterile conditions. Then, they sequenced the genomes of the bacteria found in the samples. They expected to find bacteria from the vaginal flora, due to its proximity, but instead, the microbes were similar to those found in the mouth, however in much lower abundance.

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Studies uncover 500 “hidden” microbes in the gut

Over the last few years, scientists have found that the microbes hosted in the digestive tract (the gut microbiota or gut flora) perform key functions for health. Digestion, immunity and even mental health are extremely dependent on tasks carried out by the gut bacteria.

Now, two studies have found that the human gut hosts five hundred species of microbes – and seven million microbial genes – that were unknown until now. The proportion of the gut flora that had been hidden until now may hold essential information on the origin of a range of diseases (IBD and metabolic syndrome, among others), as well as the clues on how to cure them.

The two studies were published in Nature Biotechnology in July, and come from the efforts of the MetaHIT (METAgenomics of the Human Intestinal Tract) project, a European consortium working to explore the composition of human gut microbiota.

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White bread discovered to be a good ally of our gut microbiota

Baguette and sliced bread lovers, we’ve got good news for you! For years,  it’s been criticized for its bad nutritional reputation and has been shunned as a mere glutinous slab lacking any health benefits, but white bread may help boost some of the beneficial gut microbes, according to a new paper recently published in the Journal of Agricultural and Food Chemistry.

It’s been known for decades that the close relationship between health and gut microbiota and that a healthy diet is essential for maintaining a balanced and rich population of gut bacteria. Up until now, a large number of studies had focused, precisely, on the effects of the food we eat on our gut flora, especially dietary fibre. In contrast, there was little to no information on other highly correlated diet components, such as polyphenols. A team of researchers from the University of Oviedo and the Spanish Research Council (CSIC) wanted to close that gap and set out to explore the association between gut microbiota composition and the intake of both fibres and polyphenols (common in much of what we consume like fruit, tea, spices, chocolate or wine) in a regular diet. Read more

Gender, education, and breastfeeding determine ones microbe mix

The mixture of microbes that live in a person’s body (and play a key-role for that person’s health) depend on a few, crucial facts of his or her life history. Gender, education, and whether the person was breastfed or not, shape the bacterial populations of the organism.

For example, a person with higher education has a different mix of microbes in his/her gut (the gut flora or gut microbiota) than that of a less educated one. Or one that has been breastfed has a bacterial population in the mouth and the gut that are not the same as those of a bottle-fed person.

Those key life events were identified in a study published recently in Nature by Tao Ding and Patrick Schloss, of the University of Michigan. Drawing data from the Human Microbiome Project and complementing it with additional measurements, the authors monitored the bacteria in eighteen body sites (mouth, nose, gut, ears, etc.) of 300 healthy individuals for almost two years. They focused on four bacterial communities, used genomic analysis to identify their presence, and measured the proportion of each one of them in each body sites. In that way, they could find the varying abundance of these four populations in the monitored individuals. Read more