Connecting gut bacteria to you in amazing ways.

OBESITY AND WEIGHT MANAGEMENT

Center for Genome Sciences, St. Louis, 2009 - Researchers seek out 154 twin pairs consisting of one lean individual and one obese individual. The fecal bacteria of each pair is then transplanted into the digestive system of specially-bred mice that do not have their own bacteria. As time passes, the mice transplanted with the lean twin’s fecal material remain a normal body weight, while their less fortunate counterparts begin to pack on the pounds, all other factors remaining constant.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2677729/

Novartis Institute for BioMedical Research, Cambridge, 2003 - A private biomedical research firm links the signaling protein (cytokine) interleuken-6 to the immunological inflammatory response and development of insulin resistance in fat cells as a precursor to obesity, adding to a growing list of clearly identifiable warning signs for fat development. 
http://www.jci.org/articles/view/19451
Soukas, Cohen, Socci, Friedman, 2000 - Leptin, which has long been termed both the fat and satiety gene for it's abundance in obese individuals and animals, is studied in relation to gene expression in adipose (fat) tissue. Researchers discover that stress response gene concentrations move in coordination with leptin levels, and hold a strong positive correlation to obesity in both humans and animals, proving that stress is a strong factor in fat development. 
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC316534/

The American Association for Laboratory Animal Sciences, Memphis, 1983 - A study conducted on sterile mice, which are specially bred to have no intestinal microorganisms, showed that those lacking digestive bacteria had to consume approximately 30% more food to extract the same amount of caloric value as those with normal bacterial colonies.

http://www.ncbi.nlm.nih.gov/pubmed/6834773

Merck Research Labs, New Jersey, 2011 - Production of acetate, propionate, and butyrate (the short chain fatty acids that our bodies metabolize for energy) within the colon are observed to diminish the correlation between diet and weight gain.

http://www.plosone.org/article/info:doi/10.1371/journal.pone.0035240#s4

Department of Pathology, Emery University, Atlanta, 2010- Researchers identify gut borne protein receptors as regulators of weight and metabolism, finding their absence to cause low-grade inflammation and increased immune response (in the form of higher macrophage concentrations) from the vascular tissue surrounding fatty areas. This pattern of low-grade inflammation has long been accepted to be a near-universal trait among the obese. 

IMMUNE SYSTEM

Kimmel Center for Biology and Medecine, New York University, New York, 2009 - T-Helper Cells (Th17), which are responsible for defending the body from opportunistic infections and are also linked to auto-immune disorders when in excess, are studied in relation to the Cytophaga-Flavobacter-Bacteroidetes (CFB) bacteria present in the intestine. A statistically significant, positive, relationship is found between the ability of the body to properly deploy Th17 cells when needed, and the presence of the CFB bacteria in the intestinal tract. 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2597589/

Amgen, Inc Labs, Thousand Oaks, CA, 2001 - Researchers identify extreme dietary conditions as the main factors dictating leptin concentrations, proving that low as well as high levels of the signaling protein create disorder within the body. Low-levels of leptin are linked to poor immune system response, leaving the body open to infection, while high levels are linked to overactive immune response, leading to excess macrophage activity, which ultimately leads to low-level, systemic inflammation, obesity, the metabolic syndrome, and increased risk of auto-immune disorders such as diabetes. 

http://www.fasebj.org/content/15/14/2565.full

ANXIETY & DEPRESSION

Department of Pathology and Molecular Medicine, MacMaster University, Ontario, 2007 - Mice babies are monitored after being separated from their mothers. Along with exhibiting behavior typical with anxiety, the alienated mice show consistent reductions in bacteria and hormones commonly found in the gastrointestinal tract. Interestingly, in another study in which mice were again separated from their mothers, but given supplemental dosages of the aforementioned bacterial strains, subjects displayed minimization of the effects typically associated with depression, as well as an increase in serotonin and tryptophan levels. 

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2095679/

http://www.sciencedirect.com/science/article/pii/S0306452210010729

Mellor and Munn, 2000 - Tryptophan is discussed in relation to starvation and the suppression of the immunological response. They cite evidence which links decreased tryptophan catabolism (breakdown which facilitates utilization) to starvation and nutrient deprivation. The implications create a plausible link between dieting and depression, which has been studied extensively in relation to insufficient tryptophan levels, which are necessary for the synthesis of serotonin. 

http://www.ncbi.nlm.nih.gov/pubmed/10500295

Bailey and Coe, 1999 - Researchers discover a link between emotional stress in mothers and susceptibility to disease in their infant due to altered gut bacteria colonization during early life stages. The study, which was conducted using rhesus monkeys, presented a possible causal link between mood and microbiome composition, which laid a foundation for further work exploring the link between the microbiome, gut, and brain, known as the MGB axis.

http://www.ncbi.nlm.nih.gov/pubmed/10461128   

COGNITION & MEMORY

School of Pharmacy, Texas Tech University, Lubville, 2008 - For three months, two groups of young mice (five weeks old) are fed either a standard rat chow, or a biologically diverse (and therefore bacterially diverse) food, and then tested for cognition and memory changes. The mice that were fed the diversified food showed significant improvement in both working and long-term memory over the group of “non-diverse” rats. 

http://www.sciencedirect.com/science/article/pii/S003193840800382X

ALLERGIES

American Academy of Pediatrics, New York, 2012 - Infants born to mothers with a history of asthma are monitored for 6 years and have their asthma symptoms tested every 6 months along with a sample of their gut bacteria (ascertained from fecal samples). The results show a strong inverse relationship between the diversity among microbiota (gut bacteria) and positive indications of allergic rhinitisallergic sensitization, and peripheral blood eosinophil countall of which hold strong predictive power to the presence of allergies in children.

http://pediatrics.aappublications.org/content/130/Supplement_1/S47.1.full

AUTO-IMMUNE DISORDERS

Department of Microbiology and Cell Science, University of Florida, Gainesville, 2010 - The stool samples of 16 Finnish children, 8 with type I diabetes, 8 without, are collected with the intention of studying the relationship between the disease and bacterial microbes. The study shows a strong inverse relationship between the diversity of intestinal bacteria and the presence of autoimmune disorders in children. 

http://www.nature.com/ismej/journal/v5/n1/full/ismej201092a.html

EMOTIONAL REGULATION

Gail and Gerald Oppenheimer Family Center for the Neurobiology of Stress, Los Angeles, 2012 - A UCLA study of 36 women draws connections between brain health and supplementation of bacterial cultures ascertained from supermarket-bought yoghurt. The study found that “…the women consuming probiotics showed greater connectivity between a key brainstem region known as the periaqueductal grey and cognition-associated areas of the prefrontal cortex. The women who ate no product at all, on the other hand, showed greater connectivity of the periaqueductal grey to emotion- and sensation-related regions, while the group consuming the non-probiotic dairy product showed results in between.” This study builds on suggestions from previous research that gut bacteria and the brain form a sophisticated communication network that can affect nearly every aspect of our body’s performance. 

http://newsroom.ucla.edu/releases/changing-gut-bacteria-through-245617