Nitrogen fixation and nifH diversity in human gut microbiota
- Igai, Katsura, Itakura, Manabu, Nishijima, Suguru, Tsurumaru, Hirohito, Suda, Wataru, Tsutaya, Takumi, Tomitsuka, Eriko, Tadokoro, Kiyoshi, Baba, Jun, Odani, Shingo, Natsuhara, Kazumi, Morita, Ayako, Yoneda, Minoru, Greenhill, Andrew, Horwood, Paul, Inoue, Jun-ichi, Ohkuma, Moriya, Hongoh, Yuichi, Yamamoto, Taro, Siba, Peter, Hattori, Masahira, Minamisawa, Kiwamu, Umezaki, Masahiro
- Authors: Igai, Katsura , Itakura, Manabu , Nishijima, Suguru , Tsurumaru, Hirohito , Suda, Wataru , Tsutaya, Takumi , Tomitsuka, Eriko , Tadokoro, Kiyoshi , Baba, Jun , Odani, Shingo , Natsuhara, Kazumi , Morita, Ayako , Yoneda, Minoru , Greenhill, Andrew , Horwood, Paul , Inoue, Jun-ichi , Ohkuma, Moriya , Hongoh, Yuichi , Yamamoto, Taro , Siba, Peter , Hattori, Masahira , Minamisawa, Kiwamu , Umezaki, Masahiro
- Date: 2016
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 6, no. (2016), p. 1-11
- Full Text:
- Reviewed:
- Description: It has been hypothesized that nitrogen fixation occurs in the human gut. However, whether the gut microbiota truly has this potential remains unclear. We investigated the nitrogen-fixing activity and diversity of the nitrogenase reductase (NifH) genes in the faecal microbiota of humans, focusing on Papua New Guinean and Japanese individuals with low to high habitual nitrogen intake. A 15 N 2 incorporation assay showed significant enrichment of 15 N in all faecal samples, irrespective of the host nitrogen intake, which was also supported by an acetylene reduction assay. The fixed nitrogen corresponded to 0.01% of the standard nitrogen requirement for humans, although our data implied that the contribution in the gut in vivo might be higher than this value. The nifH genes recovered in cloning and metagenomic analyses were classified in two clusters: one comprising sequences almost identical to Klebsiella sequences and the other related to sequences of Clostridiales members. These results are consistent with an analysis of databases of faecal metagenomes from other human populations. Collectively, the human gut microbiota has a potential for nitrogen fixation, which may be attributable to Klebsiella and Clostridiales strains, although no evidence was found that the nitrogen-fixing activity substantially contributes to the host nitrogen balance. © The Author(s) 2016.
- Authors: Igai, Katsura , Itakura, Manabu , Nishijima, Suguru , Tsurumaru, Hirohito , Suda, Wataru , Tsutaya, Takumi , Tomitsuka, Eriko , Tadokoro, Kiyoshi , Baba, Jun , Odani, Shingo , Natsuhara, Kazumi , Morita, Ayako , Yoneda, Minoru , Greenhill, Andrew , Horwood, Paul , Inoue, Jun-ichi , Ohkuma, Moriya , Hongoh, Yuichi , Yamamoto, Taro , Siba, Peter , Hattori, Masahira , Minamisawa, Kiwamu , Umezaki, Masahiro
- Date: 2016
- Type: Text , Journal article
- Relation: Scientific Reports Vol. 6, no. (2016), p. 1-11
- Full Text:
- Reviewed:
- Description: It has been hypothesized that nitrogen fixation occurs in the human gut. However, whether the gut microbiota truly has this potential remains unclear. We investigated the nitrogen-fixing activity and diversity of the nitrogenase reductase (NifH) genes in the faecal microbiota of humans, focusing on Papua New Guinean and Japanese individuals with low to high habitual nitrogen intake. A 15 N 2 incorporation assay showed significant enrichment of 15 N in all faecal samples, irrespective of the host nitrogen intake, which was also supported by an acetylene reduction assay. The fixed nitrogen corresponded to 0.01% of the standard nitrogen requirement for humans, although our data implied that the contribution in the gut in vivo might be higher than this value. The nifH genes recovered in cloning and metagenomic analyses were classified in two clusters: one comprising sequences almost identical to Klebsiella sequences and the other related to sequences of Clostridiales members. These results are consistent with an analysis of databases of faecal metagenomes from other human populations. Collectively, the human gut microbiota has a potential for nitrogen fixation, which may be attributable to Klebsiella and Clostridiales strains, although no evidence was found that the nitrogen-fixing activity substantially contributes to the host nitrogen balance. © The Author(s) 2016.
A high burden of asymptomatic gastrointestinal infections in traditional communities in Papua New Guinea
- Horwood, Paul, Soli, Kevin, Maure, Tobias, Naito, Yuichi, Morita, Ayako, Natsuhara, Kazumi, Tadokoro, Kiyoshi, Baba, Jun, Odani, Shingo, Tomitsuka, Eriko, Igai, Katsura, Larkins, Jo-Ann, Siba, Peter, Pomat, William, McBryde, Emma, Umezaki, Masahiro, Greenhill, Andrew
- Authors: Horwood, Paul , Soli, Kevin , Maure, Tobias , Naito, Yuichi , Morita, Ayako , Natsuhara, Kazumi , Tadokoro, Kiyoshi , Baba, Jun , Odani, Shingo , Tomitsuka, Eriko , Igai, Katsura , Larkins, Jo-Ann , Siba, Peter , Pomat, William , McBryde, Emma , Umezaki, Masahiro , Greenhill, Andrew
- Date: 2017
- Type: Text , Journal article
- Relation: American Journal of Tropical Medicine and Hygiene Vol. 97, no. 6 (2017), p. 1872-1875
- Full Text:
- Reviewed:
- Description: Stool samples were collected from 148 healthy adults living a traditional subsistence lifestyle in Papua New Guinea and screened for enteric pathogens using real-time RT-PCR/PCR assays. Enteric pathogens were detected in a high proportion (41%) of individuals. Clear differences were observed in the detection of pathogens between highland and lowland communities. In particular, there was a marked difference in detection rates of norovirus GII (20% and 0%, respectively) and Shigella sp. (15% and 0%, respectively). Analysis of the relationship between enteric pathogen carriage and microbial community composition of participants, using box plots to compare specific normal flora population numbers, did not suggest that gut microbial composition was directly associated with pathogen carriage. This study suggests that enteric pathogens are common in healthy individuals in Papua New Guinean highland communities, presumably acting as a reservoir of infection and thus contributing to a high burden of gastrointestinal illnesses.
- Authors: Horwood, Paul , Soli, Kevin , Maure, Tobias , Naito, Yuichi , Morita, Ayako , Natsuhara, Kazumi , Tadokoro, Kiyoshi , Baba, Jun , Odani, Shingo , Tomitsuka, Eriko , Igai, Katsura , Larkins, Jo-Ann , Siba, Peter , Pomat, William , McBryde, Emma , Umezaki, Masahiro , Greenhill, Andrew
- Date: 2017
- Type: Text , Journal article
- Relation: American Journal of Tropical Medicine and Hygiene Vol. 97, no. 6 (2017), p. 1872-1875
- Full Text:
- Reviewed:
- Description: Stool samples were collected from 148 healthy adults living a traditional subsistence lifestyle in Papua New Guinea and screened for enteric pathogens using real-time RT-PCR/PCR assays. Enteric pathogens were detected in a high proportion (41%) of individuals. Clear differences were observed in the detection of pathogens between highland and lowland communities. In particular, there was a marked difference in detection rates of norovirus GII (20% and 0%, respectively) and Shigella sp. (15% and 0%, respectively). Analysis of the relationship between enteric pathogen carriage and microbial community composition of participants, using box plots to compare specific normal flora population numbers, did not suggest that gut microbial composition was directly associated with pathogen carriage. This study suggests that enteric pathogens are common in healthy individuals in Papua New Guinean highland communities, presumably acting as a reservoir of infection and thus contributing to a high burden of gastrointestinal illnesses.
- «
- ‹
- 1
- ›
- »