E H Seck1, B Senghor1, V Merhej1, D Bachar1, F Cadoret2, C Robert3, E I Azhar4, M Yasir4, F Bibi4, A A Jiman-Fatani5, D S Konate6, D Musso7, O Doumbo6,8, C Sokhna9, A Levasseur1, J C Lagier1, S Khelaifia1, M Million1, D Raoult10. 1. Aix Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France. 2. APHM, IHU-Méditerranée Infection, Marseille, France. 3. Aix Marseille Univ, IRD, APHM, VITROME, IHU-Méditerranée Infection, Marseille, France. 4. Special Infectious Agents Unit, King Fahd Medical Research Center and Medical Laboratory Technology Department, Faculty of Applied Medical Sciences, King Abdulaziz University, Jeddah, Saudi Arabia. 5. Department of Medical Microbiology and Parasitology, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia. 6. Malaria Research and Training Center, Department of Epidemiology of Parasitic Diseases, Faculty of Medicine, and Dentistry, UMI-CNRS 3189, GIRAFE-IRD-FMERIEUX, University of Science, Technique and Technology of Bamako, BP 1805, Bamako, Mali. 7. Inserm U1065, Centre Méditerranéen de Médecine Moléculaire, C3M, Université de Nice-Sophia Antipolis, 151, route St Antoine de Ginestière, BP 2 3194, 06204, Nice Cedex, France. 8. Institut Louis Malardé, Papeete, Tahiti, French Polynesia. 9. French National Research Institute for Sustainable Development, VITROME, Dakar, Senegal. 10. Aix Marseille Univ, IRD, APHM, MEPHI, IHU-Méditerranée Infection, Marseille, France. didier.raoult@gmail.com.
Abstract
BACKGROUND/ OBJECTIVES: High salt intake has been linked to several diseases including obesity and an increased risk of death; however, fecal salinity and the ability of salt to alter the gut microbiota, which was recently identified as an instrumental factor for health and disease, remains poorly explored. METHODS/ SUBJECTS: We analyzed the fecal samples of 1326 human individuals for salinity by refractometry, 572 for gut microbiota by culturomics, and 164 by 16S rRNA-targeted metagenomics. Geographical origin, age, gender, and obesity were tested as predictors of fecal salinity and halophilic diversity. All halophilic isolates were characterized by taxonogenomics and their genome sequenced. RESULTS: Fecal salinity was associated with obesity independently of geographical origin, gender, and age. The first 2 human-associated halophilic archaeal members were isolated along with 64 distinct halophilic species, including 21 new species and 41 known in the environment but not in humans. No halophiles grow in less than 1.5% salinity. Above this threshold, the richness of the halophilic microbiota was correlated with fecal salinity (r = 0.58, p < 0.0001). 16S metagenomics linked high fecal salinity to decreased diversity (linear regression, p < .035) and a depletion in anti-obesity Akkermansia muciniphila and Bifidobacterium, specifically B. longum and B. adolescentis. Genomics analysis suggested that halophilic microbes are not only transient passengers but may be residents of the human gut. CONCLUSIONS: High salt levels are associated with alteration of the gut microbial ecosystem and halophilic microbiota, as discovered during this study. Further studies should clarify if the gut microbiota alterations associated with high salt levels and the human halophilic microbiota could be causally related to human disease, such as obesity.
BACKGROUND/ OBJECTIVES: High salt intake has been linked to several diseases including obesity and an increased risk of death; however, fecal salinity and the ability of salt to alter the gut microbiota, which was recently identified as an instrumental factor for health and disease, remains poorly explored. METHODS/ SUBJECTS: We analyzed the fecal samples of 1326 human individuals for salinity by refractometry, 572 for gut microbiota by culturomics, and 164 by 16S rRNA-targeted metagenomics. Geographical origin, age, gender, and obesity were tested as predictors of fecal salinity and halophilic diversity. All halophilic isolates were characterized by taxonogenomics and their genome sequenced. RESULTS: Fecal salinity was associated with obesity independently of geographical origin, gender, and age. The first 2 human-associated halophilic archaeal members were isolated along with 64 distinct halophilic species, including 21 new species and 41 known in the environment but not in humans. No halophiles grow in less than 1.5% salinity. Above this threshold, the richness of the halophilic microbiota was correlated with fecal salinity (r = 0.58, p < 0.0001). 16S metagenomics linked high fecal salinity to decreased diversity (linear regression, p < .035) and a depletion in anti-obesity Akkermansia muciniphila and Bifidobacterium, specifically B. longum and B. adolescentis. Genomics analysis suggested that halophilic microbes are not only transient passengers but may be residents of the human gut. CONCLUSIONS: High salt levels are associated with alteration of the gut microbial ecosystem and halophilic microbiota, as discovered during this study. Further studies should clarify if the gut microbiota alterations associated with high salt levels and the human halophilic microbiota could be causally related to human disease, such as obesity.
Authors: Emanuele Rinninella; Marco Cintoni; Pauline Raoul; Antonio Gasbarrini; Maria Cristina Mele Journal: Int J Environ Res Public Health Date: 2020-11-27 Impact factor: 3.390
Authors: S Konate; A Camara; C I Lo; M Tidjani Alou; A Hamidou Togo; S Niare; N Armstrong; A Djimdé; M A Thera; F Fenollar; D Raoult; M Million Journal: New Microbes New Infect Date: 2021-04-27
Authors: Tracey L K Bear; Julie E Dalziel; Jane Coad; Nicole C Roy; Christine A Butts; Pramod K Gopal Journal: Adv Nutr Date: 2020-07-01 Impact factor: 8.701