Food Microbiology Commons^™

Experimental Evaluation Of The Importance Of Colonization History In Early-Life Gut Microbiota Assembly, Inés Martínez, Maria X. Maldonado-Gomez, João Carlos Gomes-Neto, Hatem Kittana, Hua Ding, Robert J. Schmaltz, Payal Joglekar, Roberto Jiménez Cardona, Nathan L Marsteller, Steven W. Kembel, Andrew K. Benson, Daniel A. Peterson, Amanda Ramer-Tait, Jens C. Walter

Department of Food Science and Technology: Faculty Publications

The factors that govern assembly of the gut microbiota are insufficiently understood. Here, we test the hypothesis that inter-individual microbiota variation can arise solely from differences in the order and timing by which the gut is colonized early in life. Experiments in which mice were inoculated in sequence either with two complex seed communities or a cocktail of four bacterial strains and a seed community revealed that colonization order influenced both the outcome of community assembly and the ecological success of individual colonizers. Historical contingency and priority effects also occurred in Rag1^-/- mice, suggesting that the adaptive immune system …

A Critical Assessment Of The “Sterile Womb” And “In Utero Colonization” Hypotheses: Implications For Research On The Pioneer Infant Microbiome, Maria Elisa Perez-Muñoz, Marie-Claire Arrieta, Amanda E. Ramer-Tait, Jens Walter

Department of Food Science and Technology: Faculty Publications

After more than a century of active research, the notion that the human fetal environment is sterile and that the neonate’s microbiome is acquired during and after birth was an accepted dogma. However, recent studies using molecular techniques suggest bacterial communities in the placenta, amniotic fluid, and meconium from healthy pregnancies. These findings have led many scientists to challenge the “sterile womb paradigm” and propose that microbiome acquisition instead begins in utero, an idea that would fundamentally change our understanding of gut microbiota acquisition and its role in human development. In this review, we provide a critical assessment of the …

Stable Engraftment Of Bifidobacterium Longum Ah1206 In The Human Gut Depends On Individualized Features Of The Resident Microbiome, María X. Maldonado-Gómez, Inés Martínez, Francesca Bottacini, Amy O’Callaghan, Marco Ventura, Douwe Van Sinderen, Benjamin Hillmann, Pajau Vangay, Dan Knights, Robert W. Hutkins, Jens Walter

Department of Food Science and Technology: Faculty Publications

Live bacteria (such as probiotics) have long been used to modulate gut microbiota and human physiology, but their colonization is mostly transient. Conceptual understanding of the ecological principles as they apply to exogenously introduced microbes in gut ecosystems is lacking. We find that, when orally administered to humans, Bifidobacterium longum AH1206 stably persists in the gut of 30% of individuals for at least 6 months without causing gastrointestinal symptoms or impacting the composition of the resident gut microbiota. AH1206 engraftment was associated with low abundance of resident B. longum and underrepresentation of specific carbohydrate utilization genes in the pre-treatment microbiome. …

Fungi In The Healthy Human Gastrointestinal Tract, Heather E. Hallen-Adams, Mallory J. Suhr

Department of Food Science and Technology: Faculty Publications

Many species of fungi have been detected in the healthy human gut; however, nearly half of all taxa reported have only been found in one sample or one study. Fungi capable of growing in and colonizing the gut are limited to a small number of species, mostly Candida yeasts and yeasts in the family Dipodascaceae (Galactomyces, Geotrichum, Saprochaete). Malassezia and the filamentous fungus Cladosporium are potential colonizers; more work is needed to clarify their role. Other commonly-detected fungi come from the diet or environment but either cannot or do not colonize (Penicillium and Debaryomyces species, which are …

Prebiotics And Synbiotics: Dietary Strategies For Improving Gut Health, Janina A. Krumbeck, Maria X. Maldonado-Gomez, Amanda E. Ramer-Tait, Robert W. Hutkins

Department of Food Science and Technology: Faculty Publications

Purpose of review — A wide range of dietary carbohydrates, including prebiotic food ingredients, fermentable fibers, and milk oligosaccharides, are able to produce significant changes in the intestinal microbiota. These shifts in the microbial community are often characterized by increased levels of bifidobacteria and lactobacilli. More recent studies have revealed that species of Faecalibacterium, Akkermansia, and other less well studied members may also be enriched. We review the implications of these recent studies on future design of prebiotics and synbiotics to promote gastrointestinal health.

Recent findings — Investigations assessing the clinical outcomes associated with dietary modification of the …

Diversity Of Yeast And Mold Species From A Variety Of Cheese Types, Nabaraj Banjara, Mallory J. Suhr, Heather E. Hallen-Adams

Department of Food Science and Technology: Faculty Publications

To generate a comprehensive profile of viable fungi (yeasts and molds) on cheese as it is purchased by consumers, 44 types of cheese were obtained from a local grocery store from 1 to 4 times each (depending on availability) and sampled. Pure cultures were obtained and identified by DNA sequence of the ITS region, as well as growth characteristics and colony morphology. The yeast Debaryomyces hansenii was the most abundant fungus, present in 79 % of all cheeses and 63 % of all samples. Penicillium roqueforti was the most common mold, isolated from a variety of cheeses in addition to …

Sourdough Lactic Acid Bacteria As Antifungal And Mycotoxin-Controlling Agents, Yousef I. Hassan, Ting Zhou, Lloyd B. Bullerman

Department of Food Science and Technology: Faculty Publications

Sourdough starter cultures are rich sources of endogenous lactic acid bacteria. The extended shelf lives of sourdough breads are attributed to a large array of organic acids and low-molecular-weight metabolites produced during the fermentation process. Different species belonging to the lactic acid bacteria group of microorganisms, mainly Lactobacillus and Leuconostoc, are increasingly gaining the attention as possible means for inhibiting mold growth in animal feed and human food chains. In addition, certain lactic acid bacteria strains isolated from sourdough starters were also shown to reduce mycotoxins concentrations in contaminated products either by binding or degradation. This short review will …

Characterization Of The Ecological Role Of Genes Mediating Acid Resistance In Lactobacillus Reuteri During Colonization Of The Gastrointestinal Tract, Janina A. Krumbeck, Nathan L Marsteller, Steven Frese, Daniel A. Peterson, Amanda Ramer-Tait, Robert W. Hutkins, Jens Walter

Department of Food Science and Technology: Faculty Publications

Rodent-derived strains of Lactobacillus reuteri densely colonize the forestomach of mice and possess several genes whose predicted functions constitute adaptations towards an acidic environment. The objective of this study was to systematically determine which genes of L. reuteri 100-23 contribute to tolerance towards host gastric acid secretion. Genes predicted to be involved in acid resistance were inactivated, and their contribution to survival under acidic conditions was confirmed in model gastric juice. Fitness of five mutants that showed impaired in vitro acid resistance were then compared through competition experiments in ex-germ-free mice that were either treated with omeprazole, a proton-pump inhibitor …