1.
Naturalization of the microbiota developmental trajectory of Cesarean-born neonates after vaginal seeding.
Song, SJ, Wang, J, Martino, C, Jiang, L, Thompson, WK, Shenhav, L, McDonald, D, Marotz, C, Harris, PR, Hernandez, CD, et al
Med (New York, N.Y.). 2021;2(8):951-964.e5
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Studies on model organisms show that foetal development can be modulated by microbial products from the pregnant mother’s microbiota, and early colonisation is critical for immune system development. However, natural transmission and colonisation of maternal microbes is impaired by caesarean section (CS) delivery. The aim of this study was to determine the effect of restoring exposure to maternal vaginal fluids after CS birth. This study is a large observational study of 177 infants born to 174 mothers. Physicians assessed healthy mothers who were set to deliver vaginally or by scheduled CS. Results demonstrate that microbial differences associated with delivery mode can be reduced by exposure to a vaginal microbial source at birth. In fact, birth mode significantly differentiated infant gut and skin microbiome development, and that seeding worked to adjust the trajectory of CS-delivered infants through partial restoration of microbiome features associated with a vaginal delivery. Authors conclude that restoring natural exposures at birth may be one way to reduce the risk of CS-associated diseases such as obesity, asthma, allergies, and immune disfunctions. However, randomised clinical trials on large cohorts are needed to gain conclusive evidence for microbial restoration at birth improving health outcomes.
Abstract
BACKGROUND Early microbiota perturbations are associated with disorders that involve immunological underpinnings. Cesarean section (CS)-born babies show altered microbiota development in relation to babies born vaginally. Here we present the first statistically powered longitudinal study to determine the effect of restoring exposure to maternal vaginal fluids after CS birth. METHODS Using 16S rRNA gene sequencing, we followed the microbial trajectories of multiple body sites in 177 babies over the first year of life; 98 were born vaginally, and 79 were born by CS, of whom 30 were swabbed with a maternal vaginal gauze right after birth. FINDINGS Compositional tensor factorization analysis confirmed that microbiota trajectories of exposed CS-born babies aligned more closely with that of vaginally born babies. Interestingly, the majority of amplicon sequence variants from maternal vaginal microbiomes on the day of birth were shared with other maternal sites, in contrast to non-pregnant women from the Human Microbiome Project (HMP) study. CONCLUSIONS The results of this observational study prompt urgent randomized clinical trials to test whether microbial restoration reduces the increased disease risk associated with CS birth and the underlying mechanisms. It also provides evidence of the pluripotential nature of maternal vaginal fluids to provide pioneer bacterial colonizers for the newborn body sites. This is the first study showing long-term naturalization of the microbiota of CS-born infants by restoring microbial exposure at birth. FUNDING C&D, Emch Fund, CIFAR, Chilean CONICYT and SOCHIPE, Norwegian Institute of Public Health, Emerald Foundation, NIH, National Institute of Justice, Janssen.
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Effect of Lactobacillus rhamnosus HN001 on carriage of Staphylococcus aureus: results of the impact of probiotics for reducing infections in veterans (IMPROVE) study.
Eggers, S, Barker, AK, Valentine, S, Hess, T, Duster, M, Safdar, N
BMC infectious diseases. 2018;18(1):129
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The bacteria Staphylococcus aureus (S. aureus) is found in the digestive tract, nostrils, mouth and armpits. Methicillin-resistant S. aureus (MRSA) is responsible for several difficult-to-treat infections in humans. Probiotics are emerging as an alternative to antibiotics in preventing or treating bacterial infections. This randomised controlled trial aimed to determine the ability of Lactobacillus rhamnosus (L. rhamnosus) HN001 to reduce S. aureus at several different body sites. Participants in the study were mostly male, with an average age of 64 years, and all carriers of S. aureus in one or more body sites. Participants were organised into groups depending on whether S. aureus was found within the gastrointestinal tract (GI) or in other body sites (extra-GI), and given either L. rhamnosus HN001 probiotic, or a placebo for four weeks. Subjects given the probiotic had 15% lower levels of S. aureus in their stool samples than those given the placebo at the end of the trial. They also had 73% reduced odds of methicillin-susceptible S. aureus (MSSA) presence, and 83% reduced odds of any S. aureus presence in the stool sample compared to the placebo group. No other sampling sites showed a significant difference in colonisation between the two groups. The authors concluded that use of daily oral L. rhamnosus HN001 reduced odds of carriage of S. aureus in the GI tract, however it did not eradicate S. aureus from other body sites. The results of the study support the use of this probiotic strain for reducing the population of S. aureus in the gut. Further studies are needed to assess the effectiveness of different probiotic strains and to compare probiotics with antibiotics in reducing S. aureus in other body sites.
Abstract
BACKGROUND Infection by Staphylococcus aureus (S. aureus) is a major cause of morbidity and mortality. Colonization by S. aureus increases the risk of infection. Little is known about decolonization strategies for S. aureus beyond antibiotics, however probiotics represent a promising alternative. A randomized controlled trial was conducted to determine the efficacy of Lactobacillus rhamnosus (L. rhamnosus) HN001 in reducing carriage of S. aureus at multiple body sites. METHODS One hundred thirteen subjects, positive for S. aureus carriage, were recruited from the William S. Middleton Memorial Medical Center, Madison, WI, USA, and randomized by initial site of colonization, either gastrointestinal (GI) or extra-GI, to 4-weeks of oral L. rhamnosus HN001 probiotic, or placebo. Nasal, oropharyngeal, and axillary/groin swabs were obtained, and serial blood and fecal samples were collected. Differences in prevalence of S. aureus carriage at the end of the 4-weeks of treatment were assessed. RESULTS The probiotic and placebo groups were similar in age, gender, and health history at baseline. S. aureus colonization within the stool samples of the extra-GI group was 15% lower in the probiotic than placebo group at the endpoint of the trial. Those in the probiotic group compared to the placebo group had 73% reduced odds (OR 0.27, 95% CI 0.07-0.98) of methicillin-susceptible S. aureus presence, and 83% reduced odds (OR 0.17, 95% CI 0.04-0.73) of any S. aureus presence in the stool sample at endpoint. CONCLUSION Use of daily oral L. rhamnosus HN001 reduced odds of carriage of S. aureus in the GI tract, however it did not eradicate S. aureus from other body sites. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT01321606 . Registered March 21, 2011.