1
|
Rasmussen TS, Mao X, Forster S, Larsen SB, Von Münchow A, Tranæs KD, Brunse A, Larsen F, Mejia JLC, Adamberg S, Hansen AK, Adamberg K, Hansen CHF, Nielsen DS. Overcoming donor variability and risks associated with fecal microbiota transplants through bacteriophage-mediated treatments. MICROBIOME 2024; 12:119. [PMID: 38951925 PMCID: PMC11218093 DOI: 10.1186/s40168-024-01820-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 04/19/2024] [Indexed: 07/03/2024]
Abstract
BACKGROUND Fecal microbiota transplantation (FMT) and fecal virome transplantation (FVT, sterile filtrated donor feces) have been effective in treating recurrent Clostridioides difficile infections, possibly through bacteriophage-mediated modulation of the gut microbiome. However, challenges like donor variability, costly screening, coupled with concerns over pathogen transfer (incl. eukaryotic viruses) with FMT or FVT hinder their wider clinical application in treating less acute diseases. METHODS To overcome these challenges, we developed methods to broaden FVT's clinical application while maintaining efficacy and increasing safety. Specifically, we employed the following approaches: (1) chemostat-fermentation to reproduce the bacteriophage FVT donor component and remove eukaryotic viruses (FVT-ChP), (2) solvent-detergent treatment to inactivate enveloped viruses (FVT-SDT), and (3) pyronin-Y treatment to inhibit RNA virus replication (FVT-PyT). We assessed the efficacy of these processed FVTs in a C. difficile infection mouse model and compared them with untreated FVT (FVT-UnT), FMT, and saline. RESULTS FVT-SDT, FVT-UnT, and FVT-ChP reduced the incidence of mice reaching the humane endpoint (0/8, 2/7, and 3/8, respectively) compared to FMT, FVT-PyT, and saline (5/8, 7/8, and 5/7, respectively) and significantly reduced the load of colonizing C. difficile cells and associated toxin A/B levels. There was a potential elimination of C. difficile colonization, with seven out of eight mice treated with FVT-SDT testing negative with qPCR. In contrast, all other treatments exhibited the continued presence of C. difficile. Moreover, the results were supported by changes in the gut microbiome profiles, cecal cytokine levels, and histopathological findings. Assessment of viral engraftment following FMT/FVT treatment and host-phage correlations analysis suggested that transfer of phages likely were an important contributing factor associated with treatment efficacy. CONCLUSIONS This proof-of-concept study shows that specific modifications of FVT hold promise in addressing challenges related to donor variability and infection risks. Two strategies lead to treatments significantly limiting C. difficile colonization in mice, with solvent/detergent treatment and chemostat propagation of donor phages emerging as promising approaches. Video Abstract.
Collapse
Affiliation(s)
- Torben Sølbeck Rasmussen
- Section of Food Microbiology, Gut Health, and Fermentation, Department of Food Science, University of Copenhagen, Rolighedsvej 26 4, 1958, Frederiksberg, Denmark.
| | - Xiaotian Mao
- Section of Food Microbiology, Gut Health, and Fermentation, Department of Food Science, University of Copenhagen, Rolighedsvej 26 4, 1958, Frederiksberg, Denmark
| | - Sarah Forster
- Section of Food Microbiology, Gut Health, and Fermentation, Department of Food Science, University of Copenhagen, Rolighedsvej 26 4, 1958, Frederiksberg, Denmark
| | - Sabina Birgitte Larsen
- Section of Food Microbiology, Gut Health, and Fermentation, Department of Food Science, University of Copenhagen, Rolighedsvej 26 4, 1958, Frederiksberg, Denmark
| | - Alexandra Von Münchow
- Section of Experimental Animal Models, Department, of Veterinary and Animal Sciences, University of Copenhagen, Ridebanevej 9 1, 1871, Frederiksberg, Denmark
| | - Kaare Dyekær Tranæs
- Section of Food Microbiology, Gut Health, and Fermentation, Department of Food Science, University of Copenhagen, Rolighedsvej 26 4, 1958, Frederiksberg, Denmark
| | - Anders Brunse
- Section of Comparative Pediatrics and Nutrition, Department of Veterinary and Animal Sciences, University of Copenhagen, Dyrlægevej 68, 1870, Frederiksberg, Denmark
| | - Frej Larsen
- Section of Food Microbiology, Gut Health, and Fermentation, Department of Food Science, University of Copenhagen, Rolighedsvej 26 4, 1958, Frederiksberg, Denmark
| | - Josue Leonardo Castro Mejia
- Section of Food Microbiology, Gut Health, and Fermentation, Department of Food Science, University of Copenhagen, Rolighedsvej 26 4, 1958, Frederiksberg, Denmark
| | - Signe Adamberg
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Axel Kornerup Hansen
- Section of Experimental Animal Models, Department, of Veterinary and Animal Sciences, University of Copenhagen, Ridebanevej 9 1, 1871, Frederiksberg, Denmark
| | - Kaarel Adamberg
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Camilla Hartmann Friis Hansen
- Section of Experimental Animal Models, Department, of Veterinary and Animal Sciences, University of Copenhagen, Ridebanevej 9 1, 1871, Frederiksberg, Denmark
| | - Dennis Sandris Nielsen
- Section of Food Microbiology, Gut Health, and Fermentation, Department of Food Science, University of Copenhagen, Rolighedsvej 26 4, 1958, Frederiksberg, Denmark.
| |
Collapse
|
2
|
Cerri FM, Basso RM, Pereira WAB, Silveira JMDS, Ferreira EDO, Haisi A, Araújo Júnior JP, Arroyo LG, de Castro YG, Silva ROS, Oliveira-Filho JPD, Borges AS. Fecal shedding of Clostridioides difficile in calves in Sao Paulo state, Brazil. Anaerobe 2024; 88:102861. [PMID: 38729514 DOI: 10.1016/j.anaerobe.2024.102861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/25/2024] [Accepted: 04/28/2024] [Indexed: 05/12/2024]
Abstract
OBJECTIVE This study aimed to evaluate the fecal shedding of C. difficile in calves on farms in Sao Paulo State, Brazil. MATERIALS AND METHODS Fecal samples (n = 300) were collected from diarrheic (n = 78) and nondiarrheic (n = 222) calves less than 60 days of age from 20 farms. Fecal samples were inoculated into enrichment broth supplemented with taurocholate and cultured under anaerobic conditions. Colonies suspected to be C. difficile were harvested for DNA extraction and then multiplex PCR for the detection of genes encoding toxins A and B and binary toxins. All toxigenic isolates were ribotyped and tested for antimicrobial susceptibility, and five selected strains were subjected to whole-genome sequencing to determine their sequence type. RESULTS AND DISCUSSION C. difficile was isolated from 29.3 % (88/300) of the samples. All toxigenic isolates (17/88, 19.3 %) were classified as ribotypes RT046 (13/17-79.47 %, A+B+ CDT-) and RT126 (4/17 = 20.53 %, A+B+ CDT+). The sequenced strains from RT046 were classified as ST35 (Clade 1), while those from RT126 were classified as ST11 (Clade 5). No associations between the epidemiological factors in any of the groups and C. difficile isolation were observed. Most of the toxigenic isolates (16/17 = 94.41 %) were classified as multidrug-resistant. Calves can be an important source of toxigenic C. difficile strains, including multidrug-resistant isolates from ribotypes commonly observed in humans.
Collapse
Affiliation(s)
- Fabrício Moreira Cerri
- Sao Paulo State University (UNESP), School of Veterinary Medicine and Animal Science (FMVZ), Botucatu, Sao Paulo, Brazil
| | - Roberta Martins Basso
- Sao Paulo State University (UNESP), School of Veterinary Medicine and Animal Science (FMVZ), Botucatu, Sao Paulo, Brazil
| | | | - Júlia Meireles da Silva Silveira
- Federal University of Rio de Janeiro (UFRJ), Paulo de Góes Institute of Microbiology (IMPG), Department of Medical Microbiology, UFRJ, Rio de Janeiro, Rio Janeiro, Brazil
| | - Eliane de Oliveira Ferreira
- Federal University of Rio de Janeiro (UFRJ), Paulo de Góes Institute of Microbiology (IMPG), Department of Medical Microbiology, UFRJ, Rio de Janeiro, Rio Janeiro, Brazil
| | - Amanda Haisi
- Sao Paulo State University (UNESP), Institute of Biotechnology (IBTEC), Botucatu, Sao Paulo, Brazil
| | | | - Luis G Arroyo
- University of Guelph, Ontario Veterinary College, Department of Clinical Studies, Guelph, Ontario, Canada
| | - Yasmin Gonçalves de Castro
- Federal University of Minas Gerais (UFMG), School of Veterinary Medicine (EV), Belo Horizonte, Minas Gerais, Brazil
| | | | - José Paes de Oliveira-Filho
- Sao Paulo State University (UNESP), School of Veterinary Medicine and Animal Science (FMVZ), Botucatu, Sao Paulo, Brazil
| | - Alexandre Secorun Borges
- Sao Paulo State University (UNESP), School of Veterinary Medicine and Animal Science (FMVZ), Botucatu, Sao Paulo, Brazil.
| |
Collapse
|
3
|
Ma L, Zhu Y, Zhu La ALT, Lourenco JM, Callaway TR, Bu D. Schizochytrium sp. and lactoferrin supplementation alleviates Escherichia coli K99-induced diarrhea in preweaning dairy calves. J Dairy Sci 2024; 107:1603-1619. [PMID: 37769949 DOI: 10.3168/jds.2023-23466] [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: 03/07/2023] [Accepted: 09/04/2023] [Indexed: 10/03/2023]
Abstract
Calf diarrhea, a common disease mainly induced by Escherichia coli infection, is one of the main reasons for nonpredator losses. Hence, an effective nonantibacterial approach to prevent calf diarrhea has become an emerging requirement. This study evaluated the microalgae Schizochytrium sp. (SZ) and lactoferrin (LF) as a nutrient intervention approach against E. coli O101:K99-induced preweaning calve diarrhea. Fifty 1-d-old male Holstein calves were randomly divided into 5 groups (n = 10): (1) control, (2) blank (no supplement or challenge), (3) 1 g/d LF, (4) 20 g/d SZ, or (5) 1 g/d LF plus 20 g/d SZ (LFSZ). The experimental period lasted 14 d. On the morning of d 7, calves were challenged with 1 × 1011 cfu of E. coli O101:K99, and rectum feces were collected on 3, 12, 24, and 168 h postchallenge for the control, LF, SZ, and LFSZ groups. The rectal feces of the blank group were collected on d 14. Data were analyzed using the mixed procedure of SAS (version 9.4; SAS Institute Inc.). The E. coli K99 challenge decreased the average daily gain (ADG) and increased feed-to-gain ratio (F:G) and diarrhea frequency (control vs. blank). Compared with the control group, the LFSZ group had a higher ADG and lower F:G, and the LFSZ and SZ groups had lower diarrhea frequency compared with the control group. In addition, the LFSZ and SZ groups have no differences in diarrhea frequency compared with the blank group. Compared with the control group, the blank group had lower serum nitric oxide (NO), endothelin-1, d-lactic acid (D-LA), and lipopolysaccharide (LPS) concentrations, as well as serum IgG, IL-1β, IL-6, IL-10, and TNF-α levels on d 7 and 14. On d 7, compared with the control group, all treatment groups had lower serum NO level, the SZ group had a lower serum D-LA concentration, and the LF and LFSZ groups had lower serum LPS concentration. On d 14, compared with the control group, the fecal microbiota of the blank group had lower Shannon, Simpson, Chao1, and ACE indexes, the LFSZ group had lower Shannon and Simpson indexes, the SZ and LFSZ groups had a higher Chao1 index, and all treatment groups had a higher ACE index. In fecal microbiota, Bifidobacterium and Actinobacteria were negatively associated with IL-10 and d-lactate, while Akkermansia was negatively associated with endothelin-1 and positively correlated with LPS, fecal scores, and d-lactate levels. Our results indicated that LF and SZ supplements could alleviate E. coli O101:K99-induced calf diarrhea individually or in combination. Supplementing 1 g/d LF and 20 g/d SZ could be a potential nutrient intervention approach to prevent bacterial diarrhea in calves.
Collapse
Affiliation(s)
- Lu Ma
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yingkun Zhu
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; School of Agriculture & Food Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - A La Teng Zhu La
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - J M Lourenco
- Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602
| | - T R Callaway
- Department of Animal and Dairy Science, University of Georgia, Athens, GA 30602
| | - Dengpan Bu
- State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; CAAS-ICRAF Joint Lab on Agroforestry and Sustainable Animal Husbandry, World Agroforestry Centre, East and Central Asia, Beijing 100193, China.
| |
Collapse
|
4
|
Bierly SA, Van Syoc EP, Westphalen MF, Miles AM, Gaeta NC, Felix TL, Hristov AN, Ganda EK. Alterations of rumen and fecal microbiome in growing beef and dairy steers fed rumen-protected Capsicum oleoresin. J Anim Sci 2024; 102:skae014. [PMID: 38227811 PMCID: PMC10873790 DOI: 10.1093/jas/skae014] [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: 09/20/2023] [Accepted: 01/15/2024] [Indexed: 01/18/2024] Open
Abstract
The microbiome has been linked to animal health and productivity, and thus, modulating animal microbiomes is becoming of increasing interest. Antimicrobial growth promoters (AGP) were once a common technology used to modulate the microbiome, but regulation and consumer pressure have decreased AGP use in food animals. One alternative to antimicrobial growth promoters are phytotherapeutics, compounds derived from plants. Capsaicin is a compound from the Capsicum genus, which includes chili peppers. Capsaicin has antimicrobial properties and could be used to manipulate the gastrointestinal microbiome of cattle. Both the rumen and fecal microbiomes are essential to cattle health and production, and modulation of either microbiome can affect both cattle health and productivity. We hypothesized that the addition of rumen-protected capsaicin to the diet of cattle would alter the composition of the fecal microbiome, but not the rumen microbiome. To determine the impact of rumen-protected capsaicin in cattle, four Holstein and four Angus steers were fed rumen-protected Capsicum oleoresin at 0 (Control), 5, 10, or 15 mg kg-1 diet dry matter. Cattle were fed in treatment groups in a 4 × 4 Latin Square design with a 21-d adaptation phase and a 7-d sample collection phase. Rumen samples were collected on day 22 at 0-, 2-, 6-, 12-, and 18-h post-feeding, and fecal swabs were collected on the last day of sample collection, day 28, within 1 h of feeding. Sequencing data of the 16s rRNA gene was analyzed using the dada2 pipeline and taxa were assigned using the SILVA database. No differences were observed in alpha diversity among fecal or rumen samples for either breed (P > 0.08) and no difference between groups was detected for either breed in rumen samples or for Angus steers in fecal samples (P > 0.42). There was a difference in beta diversity between treatments in fecal samples of Holstein steers (P < 0.01), however, a pairwise comparison of the treatment groups suggests no difference between treatments after adjusting for multiple comparisons. Therefore, we were unable to observe substantial overall variation in the rumen or fecal microbiomes of steers due to increasing concentrations of rumen-protected capsaicin. We do, however, see a trend toward increased concentrations of capsaicin influencing the fecal microbiome structure of Holstein steers despite this lack of significance.
Collapse
Affiliation(s)
- Stephanie A Bierly
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802, USA
- One Health Microbiome Center, The Pennsylvania State University, University Park, PA 16802, USA
| | - Emily P Van Syoc
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802, USA
- One Health Microbiome Center, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Mariana F Westphalen
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802, USA
| | - Asha M Miles
- Animal Genomics and Improvement Laboratory, Agricultural Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA
| | - Natalia C Gaeta
- Department of Preventive Veterinary Medicine and Animal Health, School of Veterinary Medicine and Animal Science, University of São Paulo, São Paulo 05508-270, Brazil
| | - Tara L Felix
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802, USA
| | - Alexander N Hristov
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802, USA
| | - Erika K Ganda
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802, USA
- One Health Microbiome Center, The Pennsylvania State University, University Park, PA 16802, USA
| |
Collapse
|
5
|
Du Y, Gao Y, Hu M, Hou J, Yang L, Wang X, Du W, Liu J, Xu Q. Colonization and development of the gut microbiome in calves. J Anim Sci Biotechnol 2023; 14:46. [PMID: 37031166 PMCID: PMC10082981 DOI: 10.1186/s40104-023-00856-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/16/2023] [Indexed: 04/10/2023] Open
Abstract
Colonization and development of the gut microbiome are crucial for the growth and health of calves. In this review, we summarized the colonization, beneficial nutrition, immune function of gut microbiota, function of the gut barrier, and the evolution of core microbiota in the gut of calves of different ages. Homeostasis of gut microbiome is beneficial for nutritional and immune system development of calves. Disruption of the gut microbiome leads to digestive diseases in calves, such as diarrhea and intestinal inflammation. Microbiota already exists in the gut of calf fetuses, and the colonization of microbiota continues to change dynamically under the influence of various factors, which include probiotics, diet, age, and genotype. Colonization depends on the interaction between the gut microbiota and the immune system of calves. The abundance and diversity of these commensal microbiota stabilize and play a critical role in the health of calves.
Collapse
Affiliation(s)
- Yufeng Du
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Ya Gao
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Mingyang Hu
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jinxiu Hou
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Linhai Yang
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xianghuang Wang
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenjuan Du
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Jianxin Liu
- MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China
| | - Qingbiao Xu
- College of Animal Sciences and Technology, Huazhong Agricultural University, Wuhan, 430070, China.
- MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.
| |
Collapse
|
6
|
Koutsoumanis K, Allende A, Álvarez‐Ordóñez A, Bolton D, Bover‐Cid S, Chemaly M, Davies R, De Cesare A, Herman L, Hilbert F, Lindqvist R, Nauta M, Ru G, Simmons M, Skandamis P, Suffredini E, Argüello‐Rodríguez H, Dohmen W, Magistrali CF, Padalino B, Tenhagen B, Threlfall J, García‐Fierro R, Guerra B, Liébana E, Stella P, Peixe L. Transmission of antimicrobial resistance (AMR) during animal transport. EFSA J 2022; 20:e07586. [PMID: 36304831 PMCID: PMC9593722 DOI: 10.2903/j.efsa.2022.7586] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The transmission of antimicrobial resistance (AMR) between food-producing animals (poultry, cattle and pigs) during short journeys (< 8 h) and long journeys (> 8 h) directed to other farms or to the slaughterhouse lairage (directly or with intermediate stops at assembly centres or control posts, mainly transported by road) was assessed. Among the identified risk factors contributing to the probability of transmission of antimicrobial-resistant bacteria (ARB) and antimicrobial resistance genes (ARGs), the ones considered more important are the resistance status (presence of ARB/ARGs) of the animals pre-transport, increased faecal shedding, hygiene of the areas and vehicles, exposure to other animals carrying and/or shedding ARB/ARGs (especially between animals of different AMR loads and/or ARB/ARG types), exposure to contaminated lairage areas and duration of transport. There are nevertheless no data whereby differences between journeys shorter or longer than 8 h can be assessed. Strategies that would reduce the probability of AMR transmission, for all animal categories include minimising the duration of transport, proper cleaning and disinfection, appropriate transport planning, organising the transport in relation to AMR criteria (transport logistics), improving animal health and welfare and/or biosecurity immediately prior to and during transport, ensuring the thermal comfort of the animals and animal segregation. Most of the aforementioned measures have similar validity if applied at lairage, assembly centres and control posts. Data gaps relating to the risk factors and the effectiveness of mitigation measures have been identified, with consequent research needs in both the short and longer term listed. Quantification of the impact of animal transportation compared to the contribution of other stages of the food-production chain, and the interplay of duration with all risk factors on the transmission of ARB/ARGs during transport and journey breaks, were identified as urgent research needs.
Collapse
|
7
|
The Association between Gut Microbiome Diversity and Composition and Heat Tolerance in Cattle. Microorganisms 2022; 10:microorganisms10081672. [PMID: 36014088 PMCID: PMC9414853 DOI: 10.3390/microorganisms10081672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/11/2022] [Accepted: 08/12/2022] [Indexed: 11/16/2022] Open
Abstract
Cattle are raised around the world and are frequently exposed to heat stress, whether in tropical countries or in regions with temperate climates. It is universally acknowledged that compared to those in temperate areas, the cattle breeds developed in tropical and subtropical areas have better heat tolerance. However, the underlying mechanism of heat tolerance has not been fully studied, especially from the perspective of intestinal microbiomics. The present study collected fecal samples of cattle from four representative climatic regions of China, namely, the mesotemperate (HLJ), warm temperate (SD), subtropical (HK), and tropical (SS) regions. Then, the feces were analyzed using high-throughput 16S rRNA sequencing. The results showed that with increasing climatic temperature from HLJ to SS, the abundance of Firmicutes increased, accompanied by an increasing Firmicutes to Bacteroidota ratio. Proteobacteria showed a trend of reduction from HLJ to SS. Patescibacteria, Chloroflexi, and Actinobacteriota were particularly highest in SS for adapting to the tropical environment. The microbial phenotype in the tropics was characterized by an increase in Gram-positive bacteria and a decrease in Gram-negative bacteria, aerobic bacteria, and the forming of_biofilms. Consistently, the functional abundances of organismal systems and metabolism were decreased to reduce the material and energy demands in a hot environment. Genetic information processing and information storage and processing may be how gut flora deals with hot conditions. The present study revealed the differences in the structure and function of gut microbes of cattle from mesotemperate to tropical climates and provided an important reference for future research on the mechanism of heat tolerance regulated by the gut microbiota and a potential microbiota-based target to alleviate heat stress.
Collapse
|