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Microbiology Logo Microbiology & Immunology
Te Tari Moromoroiti me te Ārai Mate

Professor Gerald Tannock

Research interests:

Gut microbiota (microbiome)

Current research:

The gut of vertebrates is home to a bacterial collection of amazing biodiversity. For example, several hundred bacterial species live together in the human colon where they form a self-regulating community. The community is often referred to as the ‘microbiota’. Obligately anaerobic bacteria predominate in the colonic microbiota. They hydrolyze plant residues from the diet that have not been digested in the small intestine. So, the gut microbiota begins the recycling of dietary waste inside the colon by degrading plant polymers and fermenting the hydrolysis products to short chain fatty acids. These fatty acids provide a source of calories for the human because they are taken up by the intestinal mucosa and incorporated into biochemical pathways. Members of the microbiota also recycle human secretions, such as mucus. Our research objectives are to understand how the members of the microbiota (referred to as commensals) live in the gut, and the consequences to the host of this life-long association with these bacteria.

Lab group

Tannock lab 2015

Blair LawleyManuela CentanniYafei Liu

Research projects

 The development of improved cow's milk formula for infants; fertilisers of bacterial growth in the bowel (prebiotics); microbiota composition associated with human health conditions/diseases; how bacterial communities work (metatranscriptomics).


Scanning electron micrograph of cultured bifidobacterial cells

Recent publications

Bacterial succession in the broiler gastrointestinal tract. Ranjitkar, S., Lawley, B., Tannock, G., Engberg, R. M. Applied and Environmental Microbiology 82:2399-2410 (2016).

Digestive-resistant carbohydrates affect lipid metabolism in rats. Samuelsson, L. M., Young, W., Fraser, K., Tannock, G. W., Lee, J., Roy, N. C. Metabolomics 12:1-13. Doi 10.1007/s11306-016-1016-7 (2016).

Synthesis, characterisation and microbial utilisation of amorphous polysugars from lactose. Daines, A, M, Smart, Z., Sims, I. M., Tannock, G. W., and Hinkley, S. F. Carbohydrate Polymers 117:223-229 (2015).

Lactobacillus reuteri 100-23 modulates urea hydrolysis in the murine stomach. Wilson CM, Loach D, Lawley B, Bell T, Sims IM, O'Toole PW, Zomer A, Tannock GW. Appl Environ Microbiol. 2014 Oct;80(19):6104-13. doi: 10.1128/AEM.01876-14. Epub 2014 Jul 25.

A functional analysis of the formyl-coenzyme A (frc) gene from Lactobacillus reuteri 100-23C. Kullin B, Tannock GW, Loach DM, Kimura K, Abratt VR, Reid SJ. J Appl Microbiol. 2014 Jun;116(6):1657-67. doi: 10.1111/jam.12500. Epub 2014 Apr 3.

Altered transcription of murine genes induced in the small bowel by administration of probiotic strain Lactobacillus rhamnosus HN001.Tannock GW, Taylor C, Lawley B, Loach D, Gould M, Dunn AC, McLellan AD, Black MA, McNoe L, Dekker J, Gopal P, Collett MA. Appl Environ Microbiol. 2014 May;80(9):2851-9. doi: 10.1128/AEM.00336-14. Epub 2014 Feb 28.

RNA-stable-isotope probing shows utilization of carbon from inulin by specific bacterial populations in the rat large bowel.Tannock GW, Lawley B, Munro K, Sims IM, Lee J, Butts CA, Roy N. Appl Environ Microbiol. 2014 Apr;80(7):2240-7. doi: 10.1128/AEM.03799-13. Epub 2014 Jan 31.

Whole-transcriptome shotgun sequencing (RNA-seq) screen reveals upregulation of cellobiose and motility operons of Lactobacillus ruminis L5 during growth on tetrasaccharides derived from barley β-glucan. Lawley B, Sims IM, Tannock GW. Appl Environ Microbiol. 2013 Sep;79(18):5661-9. doi: 10.1128/AEM.01887-13. Epub 2013 Jul 12.

Comparison of stool microbiota compositions, stool alpha1-antitrypsin and calprotectin concentrations, and diarrhoeal morbidity of Indonesian infants fed breast milk or probiotic/prebiotic-supplemented formula. Oswari H, Prayitno L, Dwipoerwantoro PG, Firmansyah A, Makrides M, Lawley B, Kuhn-Sherlock B, Cleghorn G, Tannock GW. J Paediatr Child Health. 2013 Jun 18. doi: 10.1111/jpc.12307. [Epub ahead of print]

Bowel microbiota moderate host physiological responses to dietary konjac in weanling rats. Young W, Roy NC, Lee J, Lawley B, Otter D, Henderson G, Tannock GW. J Nutr. 2013 Jul;143(7):1052-60. doi: 10.3945/jn.113.174854. Epub 2013 May 22.

Functional screening of a metagenomic library reveals operons responsible for enhanced intestinal colonization by gut commensal microbes. Yoon MY, Lee KM, Yoon Y, Go J, Park Y, Cho YJ, Tannock GW, Yoon SS. Appl Environ Microbiol. 2013 Jun;79(12):3829-38. doi: 10.1128/AEM.00581-13. Epub 2013 Apr 12.

Comparison of the compositions of the stool microbiotas of infants fed goat milk formula, cow milk-based formula, or breast milk. Tannock GW, Lawley B, Munro K, Pathmanathan SG, Zhou SJ, Makrides M, Gibson RA, Sullivan T, Prosser CG, Lowry D, Hodgkinson AJ. Appl Environ Microbiol. 2013 May;79(9):3040-8. doi: 10.1128/AEM.03910-12. Epub 2013 Mar 1.