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Wu J, Zhang J, Huang G, Zhong Y, Yang Y, Deng P. Evidence from mendelian randomization identifies several causal relationships between primary membranous nephropathy and gut microbiota. Ren Fail 2024; 46:2349136. [PMID: 38770992 PMCID: PMC11110878 DOI: 10.1080/0886022x.2024.2349136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 04/10/2024] [Indexed: 05/22/2024] Open
Abstract
BACKGROUND Research has showcased a correlation between disruptions in gut microbiota and primary membranous nephropathy (pMN), giving rise to the concept of the 'gut-kidney axis'. However, the precise relationship between gut microbiota and pMN remains elusive. Hence, this study endeavors to investigate whether a causal relationship exists between gut microbiota and pMN utilizing Mendelian randomization (MR) analysis. METHODS The primary method employed for MR analysis is the inverse variance weighting method, supplemented by MR-Egger and the weighted median method, to infer causality. This approach was validated within the pMN cohort across two distinct populations. RESULTS At the species level, the abundance of Bifidobacterium bifidum and Alistipes indistinctus was negatively correlated with the risk of pMN. Conversely, pMN was positively associated with Bacilli abundance at the class level, Lachnospiraceae abundance at the family level, and Dialister abundance at the genus level. Specifically, at the species level, pMN was positively correlated with the abundance of Ruminococcus lactaris, Dialister invisus, and Coprococcus_sp_ART55_1. CONCLUSION These findings lay the groundwork for future research exploring the interplay between pMN and the gut microbiota, with substantial implications for the prevention and treatment of pMN and its associated complications.
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Affiliation(s)
- Jianwei Wu
- Department of Medical Technology, Gannan Healthcare Vocational College, Ganzhou, China
| | - Jing Zhang
- Department of Medical Technology, Gannan Healthcare Vocational College, Ganzhou, China
| | - Gang Huang
- Department of Laboratory, GanZhou Cancer Hospital, Ganzhou, China
| | - Yinglian Zhong
- Department of Blood Transfusion, Ganzhou Fifth People’s Hospital, Ganzhou, China
| | - Yi Yang
- Department of Rheumatology and Immunology, The Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Peng Deng
- Department of Endocrinology, Department of Nephrology, Ganzhou Fifth People’s Hospital, Ganzhou, China
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Sresung M, Paisantham P, Ruksakul P, Kongprajug A, Chyerochana N, Gallage TP, Srathongneam T, Rattanakul S, Maneein S, Surasen C, Passananon S, Mongkolsuk S, Sirikanchana K. Microbial source tracking using molecular and cultivable methods in a tropical mixed-use drinking water source to support water safety plans. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 876:162689. [PMID: 36898534 DOI: 10.1016/j.scitotenv.2023.162689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2022] [Revised: 03/01/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Microbial contamination deteriorates source water quality, posing a severe problem for drinking water suppliers worldwide and addressed by the Water Safety Plan framework to ensure high-quality and reliable drinking water. Microbial source tracking (MST) is used to examine different microbial pollution sources via host-specific intestinal markers for humans and different types of animals. However, the application of MST in tropical surface water catchments that provide raw water for drinking water supplies is limited. We analyzed a set of MST markers, namely, three cultivable bacteriophages and four molecular PCR and qPCR assays, together with 17 microbial and physicochemical parameters, to identify fecal pollution from general, human-, swine-, and cattle-specific sources. Seventy-two river water samples at six sampling sites were collected over 12 sampling events during wet and dry seasons. We found persistent fecal contamination via the general fecal marker GenBac3 (100 % detection; 2.10-5.42 log10 copies/100 mL), with humans (crAssphage; 74 % detection; 1.62-3.81 log10 copies/100 mL) and swine (Pig-2-Bac; 25 % detection; 1.92-2.91 log10 copies/100 mL). Higher contamination levels were observed during the wet season (p < 0.05). The conventional PCR screening used for the general and human markers showed 94.4 % and 69.8 % agreement with the respective qPCR results. Specifically, in the studied watershed, coliphage could be a screening parameter for the crAssphage marker (90.6 % and 73.7 % positive and negative predictive values; Spearman's rank correlation coefficient = 0.66; p < 0.001). The likelihood of detecting the crAssphage marker significantly increased when total and fecal coliforms exceeded 20,000 and 4000 MPN/100 mL, respectively, as Thailand Surface Water Quality Standards, with odds ratios and 95 % confidence intervals of 15.75 (4.43-55.98) and 5.65 (1.39-23.05). Our study confirms the potential benefits of incorporating MST monitoring into water safety plans, supporting the use of this approach to ensure high-quality drinking water supplies worldwide.
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Affiliation(s)
- Montakarn Sresung
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Phongsawat Paisantham
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Pacharaporn Ruksakul
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Akechai Kongprajug
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Natcha Chyerochana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand
| | - Tharindu Pollwatta Gallage
- Program in Environmental Toxicology, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
| | - Thitima Srathongneam
- Program in Applied Biological Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok 10210, Thailand
| | - Surapong Rattanakul
- Department of Environmental Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Siriwara Maneein
- Department of Environmental Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, Bangkok 10140, Thailand
| | - Chatsinee Surasen
- Water Resources and Environment Department, Metropolitan Waterworks Authority, Bangkok 10210, Thailand
| | - Somsak Passananon
- Line of Deputy Governor (Water Production), Metropolitan Waterworks Authority, Bangkok 10210, Thailand
| | - Skorn Mongkolsuk
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok, Thailand
| | - Kwanrawee Sirikanchana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), OPS, MHESI, Bangkok, Thailand.
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3
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Nakatsuka T, Tateishi R, Koike K. Changing clinical management of NAFLD in Asia. Liver Int 2022; 42:1955-1968. [PMID: 34459096 DOI: 10.1111/liv.15046] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 07/30/2021] [Accepted: 08/21/2021] [Indexed: 02/07/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease, affecting approximately 25% of the world's population. Recently, because of the sedentary lifestyle and overnutrition resulting from urbanisation, the burden of NAFLD has rapidly increased in many Asian countries. Currently, the prevalence of NAFLD in Asia is approximately 30%, as is the case in many Western countries. In Asia, the prevalence and presentation of NAFLD vary widely across regions because of the substantial diversity in race, socioeconomic status and living environment. Furthermore, the dual aetiology of fatty liver, particularly with viral hepatitis in Asia, makes it complex and challenging to manage. Because Asians are likely to have central adiposity and insulin resistance, approximately 7%-20% of non-obese Asians with body mass indexes of less than 25 kg/m2 are estimated to have NAFLD. Accumulating evidence indicates that NAFLD is associated with various extrahepatic comorbidities such as cardiovascular disease, chronic kidney disease, malignancy, in addition to liver-specific complications. Therefore, NAFLD should be managed as a multisystem disease in conjunction with metabolic syndrome. Lifestyle modification remains the basis of NAFLD management, but few patients can achieve adequate weight loss and maintain it long term. While various pharmacological agents are in phase 3 trials for steatohepatitis, Asian patients are underrepresented in most trials. This article reviews the epidemiological trends, clinical features, optimal assessment and current management practices for NAFLD in Asia.
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Affiliation(s)
- Takuma Nakatsuka
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Japan
| | - Ryosuke Tateishi
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Japan
| | - Kazuhiko Koike
- Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Japan
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4
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Sangkaew W, Kongprajug A, Chyerochana N, Ahmed W, Rattanakul S, Denpetkul T, Mongkolsuk S, Sirikanchana K. Performance of viral and bacterial genetic markers for sewage pollution tracking in tropical Thailand. WATER RESEARCH 2021; 190:116706. [PMID: 33310444 DOI: 10.1016/j.watres.2020.116706] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/26/2020] [Accepted: 11/27/2020] [Indexed: 06/12/2023]
Abstract
Identifying sewage contamination via microbial source tracking (MST) marker genes has proven useful for effective water quality management worldwide; however, performance evaluations for these marker genes in tropical areas are limited. Therefore, this research evaluated four human-associated MST marker genes (human polyomaviruses (JC and BK viruses [HPyVs]), bacteriophage crAssphage (CPQ_056), Lachnospiraceae Lachno3, and Bacteroides BacV6-21) for tracking sewage pollution in aquatic environments of Thailand. The viral marker genes, HPyV and crAssphage were highly sensitive and specific to sewage from onsite wastewater treatment plants (OWTPs; n = 19), with no cross-detection in 120 composite swine, cattle, chicken, duck, goat, sheep, and buffalo fecal samples. The bacterial marker genes, Lachno3 and BacV6-21, demonstrated high sensitivity but moderate specificity; however, using both markers could improve specificity to >0.80 (max value of 1.00). The most abundant markers in OWTP samples were Lachno3 and BacV6-21 (5.42-8.02 and nondetect-8.05 log10 copies/100 mL), crAssphage (5.28-7.38 log10 copies/100 mL), and HPyVs (3.66-6.53 log10 copies/100 mL), respectively. Due to their increased specificity, the abundance of viral markers were further investigated in environmental waters, in which HPyVs showed greater levels (up to 4.33 log10 copies/100 mL) and greater detection rates (92.7%) in two coastal beaches (n = 41) than crAssphage (up to 3.51 log10 copies/100 mL and 56.1%). HPyVs were also found at slightly lower levels (up to 5.10 log10 copies/100 mL), but at higher detection rates (92.6%), in a freshwater canal (n = 27) than crAssphage (up to 5.21 log10 copies/100 mL and 88.9%). HPyVs and crAssphage marker genes were identified as highly sensitive and specific for tracking sewage pollution in aquatic environments of Thailand. This study underlines the importance of characterizing and validating MST markers in host groups and environmental waters before including them in a water quality management toolbox.
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Affiliation(s)
- Watsawan Sangkaew
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, 54 Kampangpetch 6 Road, Laksi, Bangkok, 10210, Thailand
| | - Akechai Kongprajug
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, 54 Kampangpetch 6 Road, Laksi, Bangkok, 10210, Thailand
| | - Natcha Chyerochana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, 54 Kampangpetch 6 Road, Laksi, Bangkok, 10210, Thailand
| | - Warish Ahmed
- CSIRO Land and Water, Ecosciences Precinct, 41 Boggo Road, Qld 4102, Australia
| | - Surapong Rattanakul
- Department of Environmental Engineering, Faculty of Engineering, King Mongkut's University of Technology Thonburi, 126 Pracha Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140, Thailand
| | - Thammanitchpol Denpetkul
- Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, 420/6 Ratchawithi Road, Ratchathewi, Bangkok 10400, Thailand
| | - Skorn Mongkolsuk
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, 54 Kampangpetch 6 Road, Laksi, Bangkok, 10210, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, 272 Rama 6 Road, Ratchathevi, Bangkok, 10400, Thailand
| | - Kwanrawee Sirikanchana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, 54 Kampangpetch 6 Road, Laksi, Bangkok, 10210, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, 272 Rama 6 Road, Ratchathevi, Bangkok, 10400, Thailand.
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5
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Eslam M, Sarin SK, Wong VWS, Fan JG, Kawaguchi T, Ahn SH, Zheng MH, Shiha G, Yilmaz Y, Gani R, Alam S, Dan YY, Kao JH, Hamid S, Cua IH, Chan WK, Payawal D, Tan SS, Tanwandee T, Adams LA, Kumar M, Omata M, George J. The Asian Pacific Association for the Study of the Liver clinical practice guidelines for the diagnosis and management of metabolic associated fatty liver disease. Hepatol Int 2020; 14:889-919. [PMID: 33006093 DOI: 10.1007/s12072-020-10094-2] [Citation(s) in RCA: 405] [Impact Index Per Article: 101.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 09/06/2020] [Indexed: 02/06/2023]
Abstract
Metabolic associated fatty liver disease (MAFLD) is the principal worldwide cause of liver disease and affects nearly a quarter of the global population. The objective of this work was to present the clinical practice guidelines of the Asian Pacific Association for the Study of the Liver (APASL) on MAFLD. The guidelines cover various aspects of MAFLD including its epidemiology, diagnosis, screening, assessment, and treatment. The document is intended for practical use and for setting the stage for advancing clinical practice, knowledge, and research of MAFLD in adults, with specific reference to special groups as necessary. The guidelines also seek to improve patient care and awareness of the disease and assist stakeholders in the decision-making process by providing evidence-based data. The guidelines take into consideration the burden of clinical management for the healthcare sector.
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Affiliation(s)
- Mohammed Eslam
- Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and University of Sydney, Westmead, NSW, 2145, Australia.
| | - Shiv K Sarin
- Department of Hepatology, Institute of Liver and Biliary Sciences, New Delhi, India.
| | - Vincent Wai-Sun Wong
- Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
| | - Jian-Gao Fan
- Center for Fatty Liver, Department of Gastroenterology, Xin Hua Hospital Affiliated To Shanghai Jiao Tong University School of Medicine, Shanghai Key Lab of Pediatric Gastroenterology and Nutrition, Shanghai, China
| | - Takumi Kawaguchi
- Division of Gastroenterology, Department of Medicine, Kurume University School of Medicine, Kurume, Japan
| | - Sang Hoon Ahn
- Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Ming-Hua Zheng
- Department of Hepatology, MAFLD Research Center, the First Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
- Institute of Hepatology, Wenzhou Medical University, Wenzhou, China
| | - Gamal Shiha
- Hepatology and Gastroenterology Unit, Internal Medicine Department, Faculty of Medicine, Mansoura University, Mansoura, Egypt
- Egyptian Liver Research Institute and Hospital (ELRIAH), Sherbin, El Mansoura, Egypt
| | - Yusuf Yilmaz
- Department of Gastroenterology, School of Medicine, Marmara University, Istanbul, Turkey
- Institute of Gastroenterology, Marmara University, Istanbul, Turkey
| | - Rino Gani
- Department of Internal Medicine, Hepatobiliary Division, Dr. Cipto Mangunkusumo National General Hospital, Universitas Indonesia, Pangeran Diponegoro Road No. 71st, Central Jakarta, 10430, Indonesia
| | - Shahinul Alam
- Department of Hepatology, Bangabandhu Sheikh Mujib Medical University, Shahbag, Dhaka, Bangladesh
| | - Yock Young Dan
- Department of Medicine, Yong Loo Lin School of Medicine, National University Singapore, Singapore, Singapore
| | - Jia-Horng Kao
- Graduate Institute of Clinical Medicine, National Taiwan University College of Medicine, National Taiwan University, 1 Chang-Te Street, Taipei, 10002, Taiwan
- Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
- Hepatitis Research Center, National Taiwan University, National Taiwan University Hospital, Taipei, Taiwan
- Department of Medical Research, National Taiwan University, National Taiwan University Hospital, Taipei, Taiwan
| | - Saeed Hamid
- Department of Medicine, Aga Khan University, Karachi, Pakistan
| | - Ian Homer Cua
- Institute of Digestive and Liver Diseases, St. Luke's Medical Center, Global City, Philippines
| | - Wah-Kheong Chan
- Gastroenterology and Hepatology Unit, Department of Medicine, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Diana Payawal
- Department of Medicine, Cardinal Santos Medical Center, Mandaluyong, Philippines
| | - Soek-Siam Tan
- Department of Hepatology, Selayang Hospital, Batu Caves, Malaysia
| | - Tawesak Tanwandee
- Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Leon A Adams
- Medical School, Faculty of Medicine and Health Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Manoj Kumar
- Department of Hepatology, Institute of Liver and Biliary Sciences, New Delhi, India
| | - Masao Omata
- Department of Gastroenterology, Yamanashi Central Hospital, Yamanashi, Japan
- University of Tokyo, Tokyo, Japan
| | - Jacob George
- Storr Liver Centre, Westmead Institute for Medical Research, Westmead Hospital and University of Sydney, Westmead, NSW, 2145, Australia.
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6
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Gordon CA, Krause L, McManus DP, Morrison M, Weerakoon KG, Connor MC, Olveda RM, Ross AG, Gobert GN. Helminths, polyparasitism, and the gut microbiome in the Philippines. Int J Parasitol 2020; 50:217-225. [PMID: 32135180 DOI: 10.1016/j.ijpara.2019.12.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 12/10/2019] [Accepted: 12/18/2019] [Indexed: 12/19/2022]
Abstract
Polyparasitism, involving soil-transmitted helminths. and Schistosoma blood flukes, is common in low to middle income countries. These helminths impact on the gut environment and can cause changes to the gut microbiome composition. Here we examined the gut microbiome in individuals with polyparasitism from two human cohorts in the Philippines utilising DNA sequencing-based profiling. Multiple helminth species infections were high with 70.3% of study participants harbouring at least two parasite species, and 16% harbouring at least five species. Increased numbers of helminth co-infections, in particular with the gut-resident soil-transmitted helminths, were significantly associated with increased bacterial diversity; however no significant parasite-gut microbiome associations were evident for individuals infected only with Schistosoma japonicum. In general, a healthy gut is associated with high bacterial diversity, which in these human cohorts may be the result of helminth-mediated immune modulation, or due to changes in the gut environment caused by these parasitic helminths.
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Affiliation(s)
- Catherine A Gordon
- Molecular Parasitology Laboratory, Immunology Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Lutz Krause
- University of Queensland Diamantina Institute, Faculty of Medicine, Translational Research Institute, Brisbane, Australia
| | - Donald P McManus
- Molecular Parasitology Laboratory, Immunology Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia
| | - Mark Morrison
- University of Queensland Diamantina Institute, Faculty of Medicine, Translational Research Institute, Brisbane, Australia
| | - Kosala G Weerakoon
- Molecular Parasitology Laboratory, Immunology Division, QIMR Berghofer Medical Research Institute, Brisbane, Australia; School of Public Health, University of Queensland, Brisbane, Australia; Department of Parasitology, Faculty of Medicine and Allied Sciences, Rajarata University of Sri Lanka, Saliyapura, Sri Lanka
| | - Mairead C Connor
- School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom
| | - Remigio M Olveda
- Department of Immunology, Research Institute of Tropical Medicine, Manilla, Philippines
| | - Allen G Ross
- Menzies Health Institute Queensland, Gold Coast, Australia
| | - Geoffrey N Gobert
- School of Biological Sciences, Queen's University Belfast, Belfast, United Kingdom.
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Kongprajug A, Chyerochana N, Somnark P, Leelapanang Kampaengthong P, Mongkolsuk S, Sirikanchana K. Human and animal microbial source tracking in a tropical river with multiple land use activities. Int J Hyg Environ Health 2019; 222:645-654. [PMID: 30686524 DOI: 10.1016/j.ijheh.2019.01.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2018] [Revised: 12/26/2018] [Accepted: 01/17/2019] [Indexed: 12/27/2022]
Abstract
The enhancement and restoration of the water quality of deteriorating surface water resources can be challenging, particularly for rivers with multiple usages, such as agriculture, animal husbandry, human residence, and industries. Recently, the performance of DNA-based microbial source tracking (MST) indicators detected by end-point and quantitative PCR assays for identifying sources of fecal pollution from human sewage, swine, and cattle and non-host-specific (universal) fecal pollution in the Tha Chin River basin, Thailand, was evaluated. The present study monitored these validated MST markers and various physicochemical and microbial water quality parameters in samples collected from twelve stations along the Tha Chin River during four sampling events in the wet and dry seasons. No significant difference in precipitation was observed between the wet and dry samplings. Universal markers (both PCR and qPCR) were detected in all 48 samples, indicating persistent and continuing fecal contamination. The sewage- and swine-specific qPCR marker concentrations did not vary among the sampling events, whereas cattle-specific qPCR markers were detected only in the wet season. Animal-specific markers were detected in the lower Tha Chin River section, which is characterized by intensive animal farming. Sewage-specific markers were also found in the lower section and near an upstream residential area. The high agreement (87.5-100%) between the PCR and qPCR results suggested that PCR could serve as a lower-cost MST screening test that requires less technical expertise. A multivariate analysis conducted using the survival analysis procedure to include censored data also emphasized the high pollution in the lower section of the river at all sampling events. Universal and swine-specific markers showed moderate correlations with microbial indicators, including total coliforms, fecal coliforms, E. coli, and enterococci. None of the MST markers or microbial parameters were associated with the measured physicochemical parameters. This study provides the first evaluation of MST markers for monitoring surface freshwater in Thailand, and the findings might aid the pollution surveillance of impaired water bodies and the development of strategies for improving their water quality.
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Affiliation(s)
- Akechai Kongprajug
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand
| | - Natcha Chyerochana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand
| | - Pornjira Somnark
- Applied Biological Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok, 10210, Thailand
| | - Pinida Leelapanang Kampaengthong
- Water Quality Management Bureau, Pollution Control Department, Ministry of Natural Resources and Environment, Bangkok, 10400, Thailand
| | - Skorn Mongkolsuk
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Bangkok, 10400, Thailand
| | - Kwanrawee Sirikanchana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Bangkok, 10210, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Bangkok, 10400, Thailand.
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8
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Somnark P, Chyerochana N, Mongkolsuk S, Sirikanchana K. Performance evaluation of Bacteroidales genetic markers for human and animal microbial source tracking in tropical agricultural watersheds. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 236:100-110. [PMID: 29414329 DOI: 10.1016/j.envpol.2018.01.052] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 12/21/2017] [Accepted: 01/17/2018] [Indexed: 06/08/2023]
Abstract
Microbial source tracking (MST) DNA-based assays have been used to successfully solve fecal pollution problems in many countries, particularly in developed nations. However, their application in developing countries has been limited but continues to increase. In this study, sixteen endpoint and quantitative PCR (qPCR) assays targeting universal and human-, swine-, and cattle-specific Bacteroidales gene markers were modified for endpoint PCR, evaluated for their performance with sewage and fecal samples from the Tha Chin watershed and subsequently validated with samples from the Chao Phraya watershed, Thailand. Sample sizes of 81 composite samples (from over 1620 individual samples) of farm animals of each type as well as 19 human sewage samples from the Tha Chin watershed were calculated using a stratified random sampling design to achieve a 90% confidence interval and an expected prevalence (i.e., desired assay's sensitivity) of 0.80. The best universal and human-, swine-, and cattle-specific fecal markers were BacUni EP, HF183/BFDrev EP, Pig-2-Bac EP, and Bac3 assays, respectively. The detection limits for these assays ranged from 30 to 3000 plasmid copies per PCR. The positive predictive values were high in universal and swine- and cattle-specific markers (85-100%), while the positive predictive value of the human-specific assay was 52.2%. The negative predictive values in all assays were relatively high (90.8-100%). A suite of PCR assays in Thailand was established for potential MST use in environmental waters, which supports the worldwide applicability of Bacteroidales gene markers. This study also emphasizes the importance of using a proper sample size in assessing the performance of MST markers in a new geographic region.
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Affiliation(s)
- Pornjira Somnark
- Applied Biological Sciences, Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Lak Si, Bangkok, Thailand
| | - Natcha Chyerochana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok, Thailand
| | - Skorn Mongkolsuk
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok, Thailand; Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand
| | - Kwanrawee Sirikanchana
- Research Laboratory of Biotechnology, Chulabhorn Research Institute, Lak Si, Bangkok, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), Ministry of Education, Bangkok, Thailand.
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The abundance of health-associated bacteria is altered in PAH polluted soils-Implications for health in urban areas? PLoS One 2017; 12:e0187852. [PMID: 29145477 PMCID: PMC5690629 DOI: 10.1371/journal.pone.0187852] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2017] [Accepted: 10/29/2017] [Indexed: 01/01/2023] Open
Abstract
Long-term exposure to polyaromatic hydrocarbons (PAHs) has been connected to chronic human health disorders. It is also well-known that i) PAH contamination alters soil bacterial communities, ii) human microbiome is associated with environmental microbiome, and iii) alteration in the abundance of members in several bacterial phyla is associated with adverse or beneficial human health effects. We hypothesized that soil pollution by PAHs altered soil bacterial communities that had known associations with human health. The rationale behind our study was to increase understanding and potentially facilitate reconsidering factors that lead to health disorders in areas characterized by PAH contamination. Large containers filled with either spruce forest soil, pine forest soil, peat, or glacial sand were left to incubate or contaminated with creosote. Biological degradation of PAHs was monitored using GC-MS, and the bacterial community composition was analyzed using 454 pyrosequencing. Proteobacteria had higher and Actinobacteria and Bacteroidetes had lower relative abundance in creosote contaminated soils than in non-contaminated soils. Earlier studies have demonstrated that an increase in the abundance of Proteobacteria and decreased abundance of the phyla Actinobacteria and Bacteroidetes are particularly associated with adverse health outcomes and immunological disorders. Therefore, we propose that pollution-induced shifts in natural soil bacterial community, like in PAH-polluted areas, can contribute to the prevalence of chronic diseases. We encourage studies that simultaneously address the classic “adverse toxin effect” paradigm and our novel “altered environmental microbiome” hypothesis.
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Cupul-Uicab LA, Terrazas-Medina EA, Hernández-Ávila M, Longnecker MP. In utero exposure to DDT and incidence of diarrhea among boys from tropical Mexico. ENVIRONMENTAL RESEARCH 2017; 159:331-337. [PMID: 28841520 PMCID: PMC5623652 DOI: 10.1016/j.envres.2017.08.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/09/2017] [Accepted: 08/14/2017] [Indexed: 05/30/2023]
Abstract
BACKGROUND A higher incidence rate (IR) of acute gastrointestinal (GI) infections associated with prenatal exposure to p,p'-DDE was suggested by the results in two studies. Given the high mortality rate due to childhood diarrhea in some countries with ongoing use of DDT, additional data on this association is relevant for those making decisions about vector-borne disease control. OBJECTIVE To evaluate whether higher levels of prenatal exposure to p,p'-DDE and p,p'-DDT increase the risk of having diarrhea in a birth cohort of boys from tropical Mexico. METHODS Our analysis was based on 747 boys whose exposure was measured in maternal serum collected at delivery (2002-2003). Mothers reported the number of diarrhea episodes of their children during in-person interviews. The median age of the children at their last interview was 21.4 months. Poisson regression models were fitted to estimate adjusted incidence rate ratios (aIRR) of diarrhea by levels of p,p'-DDE and p,p'-DDT. RESULTS Overall, there were 1.7 episodes of diarrhea per child-year. Among those in the highest category of exposure (> 9µg DDE/g serum lipid), the aIRR for diarrhea was 1.14 (95% CI: 0.94, 1.30) compared to those in the lowest category of exposure (≤ 3µg/g). Among boys living in the urban area, the corresponding aIRR was 1.39 (95% CI: 1.07-1.80). Among rural boys, no associations emerged. CONCLUSION Although the results were consistent with a small positive association, the overall estimate was not precise. While urban boys in this study appeared to be more susceptible to DDE-associated diarrhea, a ready explanation for such increased susceptibility was not apparent.
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Affiliation(s)
- Lea A Cupul-Uicab
- Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos 62100, Mexico; Hospital Regional de Alta Especialidad de la Península de Yucatán, Mérida, Yucatán 97130, Mexico
| | - Efraín A Terrazas-Medina
- Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos 62100, Mexico.
| | - Mauricio Hernández-Ávila
- Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos 62100, Mexico
| | - Matthew P Longnecker
- Epidemiology Branch, National Institute of Environmental Health Sciences, NIH/DHHS/USA, Research Triangle Park, NC 27709, USA
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Distinctive Intestinal Lactobacillus Communities in 6-Month-Old Infants From Rural Malawi and Southwestern Finland. J Pediatr Gastroenterol Nutr 2015; 61:641-8. [PMID: 26049782 DOI: 10.1097/mpg.0000000000000878] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE Our aim was to compare the composition and diversity of Lactobacillus microbiota in infants living in Malawi and Southwestern Finland. METHODS The composition and diversity of the Lactobacillus group was analyzed in the feces of healthy 6-month-old infants living in rural Malawi (n = 44) and Southwestern Finland (n = 31), using the quantitative polymerase chain reaction method and PCR-denaturing gradient gel electrophoresis fingerprinting. RESULTS Malawian infants had higher counts of lactobacilli than their Finnish counterparts (7.45 log cells/g vs 6.86 log cells/g, P < 0.001, respectively) and the Lactobacillus community was richer and more diverse in the Malawian infants. Leuconostoc citreum and Weissella confusa were the predominant species in both study groups, but Malawian infants were more often colonized by these species (100% vs 74.2%, P < 0.001; 95.5% vs 41.9%, P < 0.001, respectively). Moreover, Lactobacillus ruminis, Lactobacillus gasseri, Lactobacillus acidophilus, and Lactobacillus mucosae were detected more often in the Malawian infants (59.1% vs 0.0%, P < 0.001; 38.6% vs 9.7%, P = 0.004; 29.5% vs 0.0%, P < 0.001; 22.7% vs 3.2%, P = 0.017, respectively). Lactobacillus casei group species, however, were only detected in the Finnish infants. CONCLUSIONS Malawian infants have a more abundant Lactobacillus microbiota with a distinct composition compared with Finnish infants. The environment, including diet and hygiene, may be among the factors influencing these differences.
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Chong CW, Ahmad AF, Lim YAL, Teh CSJ, Yap IKS, Lee SC, Chin YT, Loke P, Chua KH. Effect of ethnicity and socioeconomic variation to the gut microbiota composition among pre-adolescent in Malaysia. Sci Rep 2015; 5:13338. [PMID: 26290472 PMCID: PMC4542465 DOI: 10.1038/srep13338] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 07/15/2015] [Indexed: 01/09/2023] Open
Abstract
Gut microbiota plays an important role in mammalian host metabolism and physiological functions. The functions are particularly important in young children where rapid mental and physical developments are taking place. Nevertheless, little is known about the gut microbiome and the factors that contribute to microbial variation in the gut of South East Asian children. Here, we compared the gut bacterial richness and composition of pre-adolescence in Northern Malaysia. Our subjects covered three distinct ethnic groups with relatively narrow range of socioeconomic discrepancy. These included the Malays (n = 24), Chinese (n = 17) and the Orang Asli (indigenous) (n = 20). Our results suggested a strong ethnicity and socioeconomic-linked bacterial diversity. Highest bacterial diversity was detected from the economically deprived indigenous children while the lowest diversity was recorded from the relatively wealthy Chinese children. In addition, predicted functional metagenome profiling suggested an over-representation of pathways pertinent to bacterial colonisation and chemotaxis in the former while the latter exhibited enriched gene pathways related to sugar metabolism.
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Affiliation(s)
- Chun Wie Chong
- Department of Life Sciences, School of Pharmacy, International Medical University, 57000 Kuala Lumpur, Malaysia
| | - Arine Fadzlun Ahmad
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Yvonne Ai Lian Lim
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Cindy Shuan Ju Teh
- Department of Medical Microbiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Ivan Kok Seng Yap
- Department of Life Sciences, School of Pharmacy, International Medical University, 57000 Kuala Lumpur, Malaysia
| | - Soo Ching Lee
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Yuee Teng Chin
- Department of Parasitology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - P'ng Loke
- Department of Microbiology, New York University School of Medicine, 10010 New York, United States of America
| | - Kek Heng Chua
- Department of Biomedical Science, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
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Sirikanchana K, Wangkahad B, Mongkolsuk S. The capability of non-native strains of Bacteroides bacteria to detect bacteriophages as faecal indicators in a tropical area. J Appl Microbiol 2014; 117:1820-9. [PMID: 25207866 DOI: 10.1111/jam.12646] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 09/04/2014] [Accepted: 09/06/2014] [Indexed: 11/28/2022]
Abstract
AIMS To evaluate the use of nonlocal, already-available strains of phages to indicate faecal contamination in Thailand waters. METHODS AND RESULTS Phages of Bacteroides fragilis strains ATCC 700786 (RYC2056PH) and ATCC 51477 (HSP40PH) were measured in 71 human and animal wastewater samples in Thailand using a double-layer agar assay. Bacteriophage RYC2056PH was detected at concentrations comparable to representative human and animal wastewater samples from European and Mediterranean countries, with 61·7 and 33·3% above the threshold value of 100 PFU 100 ml(-1) in wastewater samples of human and animal origins, respectively. On the other hand, HSP40PH was detected at low concentrations in both human- and animal-polluted wastewaters. Moreover, RYC2056PH was found in 12 canal waters with human-influenced pollution and was not detected in 6 nonpolluted river waters being tested in this study. CONCLUSIONS The presence of RYC2056PH could indicate nonsource-specific faecal contamination in Thailand. SIGNIFICANCE AND IMPACT OF THE STUDY This study provided the first evidence that bacteriophages of the European-isolated B. fragilis strain RYC2056 could be used as nonsource-specific faecal indicators in the Southeast Asian region. The results of this study support the worldwide use of Bacteroides phages as faecal indicators.
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Affiliation(s)
- K Sirikanchana
- Translational Research Unit, Chulabhorn Research Institute, Bangkok, Thailand; Center of Excellence on Environmental Health and Toxicology, CHE, Ministry of Education, Bangkok, Thailand
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Boissière A, Tchioffo MT, Bachar D, Abate L, Marie A, Nsango SE, Shahbazkia HR, Awono-Ambene PH, Levashina EA, Christen R, Morlais I. Midgut microbiota of the malaria mosquito vector Anopheles gambiae and interactions with Plasmodium falciparum infection. PLoS Pathog 2012; 8:e1002742. [PMID: 22693451 PMCID: PMC3364955 DOI: 10.1371/journal.ppat.1002742] [Citation(s) in RCA: 337] [Impact Index Per Article: 28.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 04/26/2012] [Indexed: 12/16/2022] Open
Abstract
The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission. During their development in the mosquito vector, Plasmodium parasites undergo complex developmental steps and incur severe bottlenecks. The largest parasite losses occur in the mosquito midgut where robust immune responses are activated. Variability in P. falciparum infection levels indicates that parasite transmission is the result of complex interactions between vectors and parasites, which rely on both genetic and environmental factors. However, in contrast to genetically encoded factors, the role of environmental factors in parasite transmission has received little attention. In this study, we characterized the midgut microbiota of mosquitoes derived from diverse breeding sites using pyrosequencing. We show that the composition of the midgut microbiota in adult mosquitoes exhibits great variability, which is likely determined by bacterial richness of the larval habitats. When field mosquitoes were collected at late immature stages in natural breeding sites and the emerging females challenged with Plasmodium falciparum in the laboratory, significant correlation was observed between P. falciparum infection and the presence of Enterobacteriaceae in the mosquito midgut. Greater understanding of these malaria-bacteria interactions may lead to novel malaria control strategies.
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Affiliation(s)
- Anne Boissière
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
| | - Majoline T. Tchioffo
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, IRD-OCEAC, BP288, Yaoundé, Cameroun
| | - Dipankar Bachar
- UMR 7138 Systématique Adaptation Evolution, Université de Nice-Sophia Antipolis, Parc Valrose, France
| | - Luc Abate
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
| | - Alexandra Marie
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
| | - Sandrine E. Nsango
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, IRD-OCEAC, BP288, Yaoundé, Cameroun
- CNRS UPR 9022, Inserm U963, Université de Strasbourg, Strasbourg, France
| | - Hamid R. Shahbazkia
- UMR 7138 Systématique Adaptation Evolution, Université de Nice-Sophia Antipolis, Parc Valrose, France
- Área Departamental de Engenharia Electrónica e Computação, Faculdade de Ciências e Tecnologia, Universidade do Algarve, Faro, Portugal
| | | | - Elena A. Levashina
- CNRS UPR 9022, Inserm U963, Université de Strasbourg, Strasbourg, France
| | - Richard Christen
- UMR 7138 Systématique Adaptation Evolution, Université de Nice-Sophia Antipolis, Parc Valrose, France
| | - Isabelle Morlais
- UMR MIVEGEC (IRD 224- CNRS 5290- UM1- UM2), Montpellier, France
- Laboratoire de Recherche sur le Paludisme, IRD-OCEAC, BP288, Yaoundé, Cameroun
- * E-mail:
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De Cruz P, Prideaux L, Wagner J, Ng SC, McSweeney C, Kirkwood C, Morrison M, Kamm MA. Characterization of the gastrointestinal microbiota in health and inflammatory bowel disease. Inflamm Bowel Dis 2012; 18:372-90. [PMID: 21604329 DOI: 10.1002/ibd.21751] [Citation(s) in RCA: 79] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Accepted: 03/31/2011] [Indexed: 02/06/2023]
Abstract
The enteric bacterial flora play a key role in maintaining health. Inflammatory bowel disease is associated with quantitative and qualitative alterations in the microbiota. Early characterization of the microbiota involved culture-dependent techniques. The advent of metagenomic techniques, however, allows for structural and functional characterization using culture-independent methods. Changes in diversity, together with quantitative alterations in specific bacterial species, have been identified. The functional significance of these changes, and their pathogenic role, remain to be elucidated.
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Gerez IFA, Lee BW, van Bever HP, Shek LP. Allergies in Asia: differences in prevalence and management compared with western populations. Expert Rev Clin Immunol 2010; 6:279-89. [PMID: 20402390 DOI: 10.1586/eci.09.82] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
There is wide variability in the epidemiology and management of childhood asthma and related atopic diseases globally. Urbanized, affluent Western countries tend to have a higher prevalence of these diseases compared with Asian nations. However, recent studies have shown that the prevalence in Asia is increasing, although the rate of increase has slowed in the more developed Asian cities. Some possible causes for these differences are socioeconomic status, degree of urbanization, rates of infection, healthcare practices and genetic factors. Importantly, there are significant differences in the way asthma and allergic diseases are managed within Asia. This is of great concern because of the health implications, as these diseases are some of the most common chronic conditions that affect both adults and children. This review compares the differences in prevalence and management between Asia and the West, and discusses some of the possible reasons behind these variations.
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17
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The effects of maturation on the colonic microflora in infancy and childhood. Gastroenterol Res Pract 2009; 2009:752401. [PMID: 19763278 PMCID: PMC2744901 DOI: 10.1155/2009/752401] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 07/01/2009] [Accepted: 07/06/2009] [Indexed: 12/24/2022] Open
Abstract
The composition of colonic mircoflora and its changes with maturation have rarely been investigated in large samples. Methods. We used conventional microbiological testing to analyse the colonic flora (Kyberstatus, Institut forMicroecology, Herborn, Germany) of stool samples from 12 484 children with different intestinal and nonintestinal diagnoses. Stool samples were analysed for total colony forming units (CFU) (per g stool) and the abundance of Bifidobacteria, Bacteroides sp., Escherichia coli, Enterococcus sp., and Lactobacillus sp. with respect to age, gender. A subset of 1089 infants was analysed for monthly changes within the first year of life. Results. Total CFU and individual microbial species were highest during the first year of life, decreased within the first 2 years, and then stabilized for the remaining childhood. In infants, the total CFU rose until month 5, declined with weaning, and peaked at 9–10 months. Significant effects of age, but not of gender, were found in Bacteroides sp. and Lactobacilli. However Bacterioids sp. and Lactobacilli increased with age, while Enterococci and E. coli decreased, and Bifidobacteria remained stable. Conclusion. Colonic microflora show both a bacteria-specific and general pattern of maturation which is most profound within the first year.
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