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[[Image:Geier-mark web.jpg|right|thumb|200px|Dr Mark Geier]]
'''Positions''':
* Senior Research Officer, South Australian Research and Development Institute [[Organisations#South_Australian_Research_and_Development_Institute_(SARDI):_Poultry|(SARDI)]]
* Project Leader, [[Poultry CRC]]

===Contact===
'''Phone''': (08) 8303 7793 

'''Email''': [mailto:Geier.Mark@saugov.sa.gov.au Geier.Mark@saugov.sa.gov.au]

'''Web''': [http://www.sardi.sa.gov.au/dhtml/ss/section.php?sectID=111 SARDI - Poultry]

===Qualifications===
* B.Sc. (Hons), University of Adelaide
* PhD (Physiology), University of Adelaide

====Areas of expertise====
* Animal models of intestinal diseases
* Non-invasive testing
* Gut physiology
* Intestinal microflora and probiotics/prebiotics
* Poultry nutrition - Single bird and group energy metabolism studies
* Poultry nutrition - Large scale broiler growth studies    
* See the [http://www.sardi.sa.gov.au/pages/livestock/poultry/poultry_res_facilities.htm SARDI website] for further information 

===Research===

The objective of our research group (Led by [[Hughes, Bob|Dr. Bob Hughes]] - SARDI) is to develop effective strategies for sustainable production of chicken meat without reliance on antibiotics. 

We investigate the effects of bioactive and nutraceutical compounds on the gut health and gut function of broiler chickens. 

We aim to provide an integrated picture of the complex interactions between nutrition, mucosal immunity, the intestinal microflora, and gut structure and function, and the corresponding impacts of these factors on bird health and performance.
 
This research will benefit the Poultry Industry by the development of feeding regimens that will reduce the reliance on antibiotics, without subsequent losses in production efficiency.

=== Publications  ===

'''Journal Articles''' 

*Janardhana V, Broadway MM, Bruce MP, Lowenthal JW, Geier MS, Hughes RJ, Bean AGD. Prebiotics modulate immune responses in the gut-associated lymphoid tissue of chicken. Journal of Nutrition (2009). ''Epub May 27''. 
*Prisciandaro LD, Geier MS, Butler RN, Cummins AG, Howarth GS. Probiotics and their derivatives as treatments for inflammatory bowel disease. Inflammatory Bowel Diseases (2009). ''Epub April 16''. 
*Geier MS, Torok VA, Allison GA, Ophel-Keller K, Hughes RJ. Indigestible carbohydrates alter the intestinal microbiota but do not influence the performance of broiler chickens. Journal of Applied Microbiology (2009) 106(5):1540-1548. 
*Geier MS, Smith CL, Butler RN, Howarth GS. Small intestinal manifestations of dextran sulfate sodium consumption in rats and assessment of the effects of Lactobacillus fermentum BR11. Digestive Diseases and Sciences (2009) 54(6):1222-1228. 
*Smith CL, Geier MS, Yazbeck R, Torres DM, Butler RN, Howarth GS. Lactobacillus fermentum BR11 and fructo-oligosaccharide partially reduce jejunal inflammation in a model of intestinal mucositis in rats. Nutrition and Cancer (2008) 60(6):757-767. 
*Howarth GS, Lindsay RJ, Butler RN, Geier MS. Can emu oil ameliorate inflammatory disorders affecting the gastrointestinal system? Australian Journal of Experimental Agriculture (2008) 48(10):1276-1279. 
*Torres DM, Tooley KL, Butler RN, Smith CL, Geier MS, Howarth GS. Lyprinol™ only partially improves indicators of small intestinal integrity in a rat model of 5-fluorouracil-induced mucositis. Cancer Biology and Therapy (2008) 7(2):295-302.

*Yazbeck R, Howarth GS, Geier MS, Demuth HU, Abbott CA. Inhibiting dipeptidyl peptidase activity partially ameliorates colitis in mice. Frontiers in Bioscience (2008) 13:6850-6858.

*Mauger CA, Butler RN, Geier MS, Inglis KL, Howarth GS. Probiotic effects on 5-fluorouracil-induced mucositis assessed by the sucrose breath test in rats. Digestive Diseases and Sciences (2007) 52(3):612-619.

*Geier MS, Butler RN, Giffard PM, Howarth GS. Lactobacillus fermentum BR11, a potential new probiotic, alleviates symptoms of colitis induced by dextran sulfate sodium (DSS) in rats. International Journal of Food Microbiology (2007) 114(3):267-274.

*Geier MS, Butler RN and Howarth GS. Inflammatory bowel disease: current insights into pathogenesis and new therapeutic options; probiotics, prebiotics and synbiotics. International Journal of Food Microbiology (2007) 115(1):1-11.

*Geier MS, Butler RN, Giffard PM, Howarth GS. Prebiotic and Synbiotic Fructooligosaccharide Treatment Fails to Reduce the Severity of Experimental Colitis in Rats. Diseases of the Colon and Rectum (2007) 50(7):1061-1069.

*Kamil R, Geier MS, Butler RN, Howarth GS. Lactobacillus rhamnosus GG exacerbates intestinal ulceration in a model of indomethacin-induced enteropathy. Digestive Diseases and Sciences (2007) 52(5):1247-1252.

*Geier MS, Butler RN, Howarth GS. Probiotics, prebiotics and synbiotics: a role in chemoprevention for colorectal cancer? Cancer Biology and Therapy (2006) 5(10): 1265-1269.

*Abbott CA, Yazbeck R, Geier MS, Demuth HU, Howarth GS. Dipeptidyl peptidases and inflammatory bowel disease. Advances in Experimental Medicine and Biology (2006). 575:155-62.

*Geier MS, Tenikoff D, McCaughan GW, Yazbek R, Abbott CA, Howarth GS. Development and Resolution of Experimental Colitis in Mice with Targeted Deletion of Dipeptidyl Peptidase IV. Journal of Cellular Physiology (2005) 204(2):687-692.

*Cool JC, Dyer JL, Xian CJ, Butler RN, Geier MS, Howarth GS. Pre-treatment with Insulin-Like Growth Factor-I Partially Ameliorates 5-Fluorouracil-Induced Intestinal Mucositis in Rats. Growth Hormone and IGF Research (2005) 15(1):72-82.

<br>'''Conference Proceedings/Published Abstracts''' 

*Geier MS, Torok VA, Boulianne M, Allison GE, Janardhana V, Guo P, Bean AGD, Hughes RJ. The effects of lactoferrin on broiler performance, gut microbial communities and the intestinal mucosal immune system. Proceedings of the Australian Poultry Science Symposium 20:81-84 (2009). 
*Lindsay RJ, Geier MS, Yazbeck R, Lymn KA, Butler RN, Howarth GS. Emu oil and its effect on 5-fluorouracil-induced mucositis. Journal of Gastroenterology and Hepatology 23(4):A211 (2008). 
*Geier MS, Torok VA, Allison GE, Gibson RA, Janardhana V, Ophel-Keller K, Hughes RJ. Prebiotics and omega-3 polyunsaturated fatty acids influence the intestinal mucosal immune system and microbial communities of broiler chickens but do not improve performance. World’s Poultry Science Journal 64 (Supp 2): 337 (2008). 
*Janardhana V, Broadway MM, Bruce MP, Lowenthal JW, Geier MS, Hughes RJ, Bean AGD. Impact of feed additives on immune function in the chicken. World’s Poultry Science Journal 64 (Supp 2): 366 (2008). 
*Lindsay RJ, Howarth GS, Geier MS. The application of emu oil in intestinal health. World’s Poultry Science Journal 64 (Supp 2): 669 (2008). 
*Lindsay RJ, Geier MS, Yazbeck R, Lymn KA, Butler RN, Howarth GS. Emu oil: A potential treatment for chemotherapy-induced mucositis? World’s Poultry Science Journal 64 (Supp 2): 670 (2008). 
*Roberts AL, Moretta S, Fletcher JM, Howarth GS, Lymn KA, Geier MS, Byers S. Gastrointestinal pathology in a mouse model of mucopolysaccharidosis type IIIA (MPS IIIA). Gastroenterology 132(4):A537 Suppl. 2 (2007).

*Smith CL, Geier MS, Butler RN, Howarth GS. Dextran Sulfate Sodium-Induced Crypt Hyperplasia in the Jejunum and Ileum is Prevented by Oral Administration of Lactobacillus fermentum BR11 and Bifidobacterium lactis Bb12 to Rats. Gastroenterology 132(4):A370 Suppl. 2 (2007).

*Smith CL, Geier MS, Chapman JML, Roberts K, Butler RN and Howarth GS. Dextran Sulphate Sodium (DSS)-induced small intestinal hyperplasia is prevented by administration of Lactobacillus fermentum to rats. Journal of Gastroenterology and Hepatology 21(4): A268 (2006).

*Mauger CA, Butler RN, Geier MS, Tooley KL and Howarth GS. Use of the sucrose breath test to assess probiotic effects on small bowel injury in the rat. Journal of Gastroenterology and Hepatology 21(4): A284 (200)6.

*Geier MS, Butler RN, Howarth GS. Differential efficacy of probiotic species in amelioration of dextran sulphate sodium-induced colitis in rats. Gastroenterology 128(4):A603-A604 Suppl. 2 (2005)

*Yazbek R, Demuth HU, Geier MS, Abbott CA, Howarth GS. Inhibition of dipeptidyl peptidase IV-like activity partially ameliorates development of experimentally-induced colitis in mice. Gastroenterology 128(4):A200 Suppl. 2 (2005)

*Kamil R, Butler RN, Geier MS, Howarth GS. Lactobacillus GG but not Bifidobacterium BB12 increases severity of Indomathacin-induced intestinal ulceration in rats. Gastroenterology 128(4):A604 Suppl. 2 (2005)

*Kamil R, Butler RN, Geier MS, Howarth GS. Indomethacin-induced ulceration is differentially affected by probiotic species in rats. Journal of Gastroenterology and Hepatology, 20 Suppl. A55 (2005)

*Geier MS, Butler RN, Howarth GS. Probiotic species differentially ameliorate dextran sulphate sodium-induced colitis in rats. Journal of Gastroenterology and Hepatology, 20 Suppl. A63 (2005)

*Geier MS, Abbott CA, Tenikoff D, McCaughan GW, Howarth GS. Development and Resolution of Experimental Colitis in Dipeptidyl Peptidase IV Knockout Mice. Gastroenterology 126(4) Suppl. 2, S990 (2004).

*Geier MS, Abbott CA, Tenikoff D, Yazbek R, McCaughan GW, Howarth GS. Development and Resolution of Experimental Colitis in Dipeptidyl Peptidase IV Knockout Mice. Journal of Gastroenterology and Hepatology, 19 Suppl. A201 (2004).

*Kamil R, Cool JC, Dyer JL, Xian CJ, Butler RN, Tenikoff D, Geier MS, Howarth GS. Insulin-Like Growth Factor-I (IGF-I) Pretreatment Partially Ameliorates Intestinal Mucositis in Rats. Journal of Gastroenterology and Hepatology, 19 Suppl. A207 (2004).

*Tenikoff D, Murphy KJ, Le M, Geier MS, Butler RN, Howarth GS, Howe PR. LyprinolTM: A Potential Preventive Treatment for Experimental Inflammatory Bowel Disease (IBD). Journal of Gastroenterology and Hepatology, 19 Suppl. A209 (2004). 
*Cool JC, Dyer JL, Xian CJ, Butler RN, Tenikoff D, Geier MS, Howarth GS. Pre-treatment with insulin-like growth factor-I (IGF-I) partially ameliorates intestinal mucositis in rats. Growth Hormone and IGF Research, 14:145 (2004).

*Cool JC, Seymour-Griffin CL, Geier MS, Tenikoff D, Lee SS, Dang YP, Dandie GW and Howarth GS. Temporal Profile of Repair and Proliferation During Recovery from Indomethacin Injury in the Rat Stomach. Gastroenterology 124(4) Suppl. 1, S1212 (2003).

== See also ==

*Research project: [[Research/Understanding gut function and gut health of chickens|Understanding gut function and gut health of chickens]]

[[Category:Research & Development]][[Category:Anatomy and physiology]] [[Category:Education and training]]