This Week In Biofilms And Microbiomes: Monday August 1, 2016

A round-up of what we read last week in the media's coverage of biofilms and microbiomes research.

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This week’s most talked about news came from the leading microbiome therapeutics company, Seres Therapeutics Inc. In a press release issued on Friday, the company revealed the failure of its lead candidate, SER-109, to meet its phase 2 trial's primary endpoint of reducing Clostridium Difficile (C. diff) infection recurrence at up to 8 weeks. Earlier this year, the drug maker had published data suggesting that its pill, SER 109, which is a mix of bacterial spores designed to treat patients from recurring infection of the potentially deadly bacterium Clostridium difficile, could radically alter treatment of the gastrointestinal illness that in 2011 claimed 29,000 lives in the U.S. But results from a more advanced trial failed to show a statistically significant reduction in the risk of recurrence, with 44% of SER-109 subjects experiencing CDI recurrence at 8 weeks compared to 53% on placebo. The phase 2 trial was the first placebo-controlled and blinded study in the emerging microbiome field, according to the company. Seres Therapeutics raised $134 million in an IPO last year and made history in the process, becoming the first drug developer targeting the microbiome to go public in the U.S. But the recent news sent shock waves to the company’s share prices which plummeted by more than 75% to $8.74 a piece in pre-market trading on Friday. However, the company is still optimistic despite the trial's failure, emphasizing the technology is new and, like any new technology, had to fail at some point. "We think that SER-109 actually is a good way of getting at this for the first time," said Roger Pomerantz, President, CEO and Chairman of Seres. "We are sort of pioneering this, if you look at the literature it is not at all clear that we know the placebo rate for fecal transplants," he added after comparing the technology to the early years of the immuno-oncology and gene therapy fields. He said Seres’ priority will be to complete a full review of the clinical results and microbiome data of phase 2 clinical studies, and compare it to data from the phase I study: “Based on this information and pending discussions with the FDA, we plan to make any necessary changes to our development plans for SER-109.”The news was widely covered by many scientific and business media outlets, including BioWorld Online, GEN News, The Boston Globe and the Bloomberg.

Making it amongst the top research highlights of the week was this paper published in Science Translational Medicine. The study, led by researchers from The Saban Research Institute of Children's Hospital Los Angeles (CHLA), suggests that maternal HIV infection influences the microbiome of their HIV-uninfected infants, which may account for some of the immunological and survival differences seen in these children. A vast majority of uninfected infants born annually to HIV-positive mothers worldwide experience twice the mortality of children born to HIV-negative women, though the reasons for this have remained unclear. Based on the earlier findings that changes in human milk oligosaccharides (HMO) composition influence postnatal transmission and survival of HIV-exposed, uninfected infants, the researchers, led by Dr. Jeffrey M. Bender, of the Division of Infectious Diseases at Children’s Hospital Los Angeles, hypothesized that perturbation of both the mother’s microbiome and the mother’s breast milk HMO composition by HIV infection alters the microbiome in HIV-exposed, uninfected infants and may be the reason for some of the survival differences seen in these children. To test this theory, the scientists enrolled 50 mother-and-infant pairs from Port-au-Prince, Haiti, evenly split between HIV-positive and HIV-negative mothers, and looked broadly at the microbiomes of sample sites from each pair. Interestingly, the researchers found very few differences in the microbiomes of mothers with and without HIV infection, however, in contrast the microbiomes of HIV-exposed, uninfected infants were strikingly different from infants born to HIV-negative women in the same community. This was most clearly demonstrated in the stool composition of the HIV-exposed, uninfected infants but was also observed in the mouth and skin samples as well. How did the HIV-exposed, uninfected infants develop such clearly different microbiomes compared to those unexposed infants in the same community? The authors propose that the changes in the HMO composition of mothers’ breast milk may have downstream prebiotic effects on the growth and colonization of various bacterial species in the infant microbiome, which could potentially compromise development of the infant's immune system. The study also suggests that providing infants with important beneficial bacteria (probiotics or prebiotics) may potentially improve long-term outcomes, although this remains to be thoroughly investigated and tested. Read the press release covered by Science Daily and Scicasts.

We’d love to hear what you’ve been reading this week. Please comment below.

Richa Dandona

Partnerships and Operations Manager, Nature Partner Journals, Nature Research