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Gut InstinctExploring the Partnership Between
You and Your BellyJoanna Wilson, D.O.
Women’s HealthBoard-Certified Internal Medicine
“HUMANS ARE 99% BACTERIAL.”-Bonnie Bassler (TED talk)
Mutualism
• Humans have 10 X more bacterial cells than human cells
• Between 300-1000 species live in our intestines– 99% are anaerobes
• Intestinal bacteria have allowed us to obtain greater nutrients from our food, develop sophisticated immune systems, and the balance affects cognition and emotions
Baby’s First Gift
• Vaginal flora changes during pregnancy to bacteria which are better able to metabolize breast milk
• Bacteria introduced during vaginal delivery to germ-free babies establishes the baby’s intestinal ecosystem
Starting with a different set of tools
• Intestinal bacterial ecosystem introduced to babies born by C-section resembles skin flora of birth participants
Breast Milk is the original pre- and probiotic!Breast milk contains over 600 different kinds of bacteria and it provides oligosaccharides to feed the bacteria in the baby’s intestine. Yum!
Take a peek
A Closer Look at Your Colon Lining
Colon Bacteria: Functions in Nutrition
• Improve acquisitions of vitamins and nutrients from food– Germ-free rodents required 30% more calories to
maintain weight– Malnutrition can occur after antibiotic use
• Affect cholesterol metabolism• Generate vitamins B1, B7, K
Ground Cover
• The dominant microbiota is established in infancy and inhibits colonization by pathogens by – Occupying luminal cell
receptors– Releasing bacteriostatic
and microbicidally acting substances
Colon Bacteria: Function in Immunity
• Assist in establishment of self vs non-self recognition– Germ-free mice have higher numbers of natural-killer
cells, with resultant increase in asthma and IBD
• Mediate activity of the immune cells of the colon lining and control the intestinal lining permeability
• Communicate with spleen and liver to control immune cell response
Abnormal Immune Response to Gastrointestinal Bacteria May
Contribute to Diseases
• Autoimmune Diabetes I• Crohn’s Disease• Ulcerative Colitis
Sanitized Society
Societal Behaviors Impact Future Disease
• The drastic increase of children born without h. pylori gastric bacteria correlates very strongly with the increase in incidence of allergies and asthma in children
• Children born by C-section have a higher rate of allergies and asthma
Central Nervous System Priming
• 40 genes for learning, memory, mood, and motor control are permanently affected by the early presence of gut bacteria
• Timing is everything– Bacteria must be
established early in life for benefits to occur
Mood and Colon Bacteria• Several studies showed
germ-free mice who were inoculated with specific bacteria generated and delivered neurotransmitters to the brain, affecting anxiety, corticosteroid production, and colitis symptoms
• Human studies using yogurt with probiotics showed emotion and sensitivity were statistically different when probiotics were consumed
Colon Bacteria Alter Pain Perception
• Pain perception was reduced in rats with Bifidobacterium infantis inoculation
• Lactobacillus acidophilus induced opiod and cannabinoid receptors in intestinal epithelial cells
Bidirectional Communication Methods
• Vagus (10th cranial nerve)• Bloodstream (cytokines,
hormones, neuropeptides)
• Spinal cord
• Allow for near-instant reaction to acute change in gut environment
Neurotransmitters are Highly Preserved in Nature
Greatest concentration of serotonin is the intestines!
Bacteria Neurotransmitter Produced
Lactobacillus, Bifidobacterium GABA
Escherichia, Bacillus, Saccharomyces
Norepinephrine
Streptococcus, Escherichia, Enterococcus
Serotonin
Bacillus, Serratia Dopamine
Lactobacillus Acetylcholine
Stress and The Belly• Stress increases
permeability of the gut lining to bacteria and bacterial antigens– Activates immune
response– Changes the composition
of the gut microbiome– Alters brain
neurochemicals
– Ex: inflammation promotes E. coli proliferation
Highly Processed Diets Modify Colon Bacteria
• Sugar/sugar substitutes• High-fructose corn
syrup• Preservatives• Processed grains• Alcohol
• Appear to be either non-nutritive or harmful to gut flora
Supplements Change Colon Flora
• Isoflavones for menopause symptoms changed bacterial diversity and composition
• L-carnitine for muscle gain induces colon bacteria which convert it into a substance which causes atherosclerosis– The same manner as a
high red meat diet does
Age and Sex Differences in Colon Bacteria
• Aging causes:– Reduction in anaerobes and bifidobacteria– Increase in Enterobacter and endotoxin-producing
gram negative bacteria
• Stool pH is higher in women (less acidic)
Effect of Occupation on Colon Bacteria
• Ranchers harbored more Prevotella species– Abundant in cattle and sheep
Enterotypes- Microbiota Profiles
• 1. Bacteroides- induced by a diet high in animal protein, amino acids, and saturated fats
• 2. Prevotella- induced by a diet high in carbs/sugars
• 3. Ruminococcus
An Individual’s Microbiota is Generally Consistent Through Life
• Foundation colonies tend to be consistent over a person’s life
• About 40% of bacterial types are transient and affected by diet, lifestyle, meds
Leanness, Bacteria Type, and Calorie Absorption
Effects of Diabetes and Obesity on Colon Bacteria
• 26 Species of bacteria correlated significantly with obesity, insulin resistance, and metabolic syndrome
• Bacteria from obese people had relatively higher production of short chain fatty acids– Increased production of leptin• Increases appetite
Thin to Fat
• Inoculation of genetically thin mice with enterobacter cloacae caused weight gain
Fat to Thin
• Gastric Bypass Surgery Alters Gut Flora– Fecal samples from
bypassed colonized mice to sterile non-surgerized mice caused significant weight loss in recipients
Future Treatments of Obesity
• Using bacterial flora to change nutrient metabolism and inflammation– Changing to a lower fat/ lower carb diet– Human stool transplants from lean donors
Strain Human data
Strain Human Data
L. rhamnosus GG Immune enhancement, infectious diarrhoea in children, primary prevention of atopic dermatitis
B. lactis BB-12 Immune enhancement, diarrhoea in children
L. reuteri SD2112 Reduced absences from work, diarrhoea, immune function
B. infantis 35624 Irritable bowel syndrome (IBS)
L. casei DN114-001 Immune enhancement
B. longum BB536 Allergy symptoms, intestinal micro-ecology
L. acidophilus NCFM Symptoms of lactose intolerance, reduced small-bowel bacterial overgrowth
B. lactis HN019 (DR10) Immune enhancement, especially in elderly
B. animalis DN173-010 Normalizes intestinal transit time
L. plantarum 299V IBS, post-surgical gut nutrition
Lactobacillus casei Shirota YIT9029 Superficial bladder-cancer recurrence, intestinal microbiota, immune enhancement
L. salivarius UCC118 Inflammatory bowel disease
L. johnsonii La1 (Lj1) Immune function, Helicobacter pylori eradication
Escherichia coli Nissle 1917 Immune function, intestinal health
Saccharomyces cerevisiae (boulardii) lyo Antibiotic-associated diarrhoea, Clostridium difficile infections
S. thermophilus (most strains) Symptoms of lactose intolerance
Probiotic• Probiotics are live microorganisms which, when
administered in adequate amount, confer a health benefit on the host– Not all strains confer the same benefits– Colony Forming Units (CFU) dose varies for effectiveness– Bacteria must be able to survive ingestion
– The effect of a probiotic is likely site-specific in the colon– Sauerkraut, kimchi, pickles, yogurt, kefir, miso
(nonpasturized)– May not have long-term impact without significant diet
change
Prebiotic
• Selectively fermented ingredient that results in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefit(s) upon host health– Resistance to degradation by the host– Fermentation by intestinal microbes– Stimulate growth or activity of intestinal microorganisms
– Breast milk, leek, asparagus, Jerusalem artichoke, artichoke, garlic, onion, wheat, oat, soybean, bran, psyllium
– Fructooligosaccharides (FOS), galactooligosaccharides (GOS)
New Products May Encourage Residence of “Good Bacteria”
Fecal Transplants
• Highly effective in resistant C. difficile colitis
• Safe and inexpensive
Future Uses Of Colon Bacteria To Improve Health
• Create intestinal bacteria which promote endocrine functions, like insulin production
• Produce highly selective, non-absorbable antibiotics
• Invent drugs to alter bacteria-to-bacteria communication
• Understand probiotics to manipulate health and disease
• Transplant stool from thin people for treatment of obesity
• Improve nutrient absorption to end starvation