Module 16 Flashcards
Congenital Lactose Intolerance
Deficiency in b-galactosidase
B-galactosidase
Digestion of disaccharide lactose
Lactose Intolerance Help
Intake of fermented dairy instead of milk so LAB produce B-galacotsidase to breakdown lactose in intestine or milk
B-galactosidase not function
Lactose makes CS of intestine secrete water into intestine and lots of bacterial fermentation –> Production of H, CO2, lactic acid, and acetic acid –> loose stool, bloating, abdominal pain, flatulence
Types of Diarrhea Treatments
Infantile, Antibiotic-associated, Traveller’s
Infantile diarrhea
Several viruses and bacteria but mainly rotavirus
Leading cause of acute viral gastroenteritis in children
Group A Rotavirus (GVA) at about 440,000 deaths/year
GVA Mechanism
Enhanced permeability of gut epithelial cells to intact proteins and altered handling of antigens in enteric route
Steps of RVA
Increased permeability of intestinal wall –> More antigens across barrier –> Bigger inflammatory response
Why probiotics might help with GVA
Enhance mucosal integrity
GVA in animal models
Rodents and Pigs
Bacteria against RVA
Lactobacilli casie sp. rhamnosus strain GG and Bifidobacteria bifidum
Antibiotic-Associated Diarrhea
Otherwise unexplained diarrhea that occurs in association with antibiotics
Pseudomembranous colitis
C. diff etiological agent
Most common cause of antibiotic-associated diarrhea
C. diff
Antibiotics…
Disrupts barrier function of normal microbiota so C. diff can establish itself and produce toxin
Antibiotics for C. diff
Metronidazole and Vancomycin with recurrence common
Probiotics Prevention of C. diff
Conflict with B. longum superior to placebo for erythromycin induced diarrhea in 10 healthy and L. GG having lower incidence compared with yogurt placebo
Probiotic for C. diff
Lactobacillus GG
Treatment for C. diff times
Ongoing infection or while on antibiotics
Psuedomembraneous colitis mechanism
Exaggerated response of circulating neutrophils and monocytes due to toxin –> inflamed intestinal tissue and cell death
Traveler’s diarrhea
Many microbes but most caused by enterotoxigenic E. coli from drinking water in different countries
Results of probiotics in TD
Conflict depending on strain, vehicle, and dosage (hard to evaluate)
Prevalence of H. pylori gastritis
50% worldwide
Chronic gastritis
H. pylori
Increased risk of peptic ulcer disease
H. pylori
Increased H. pylori cancers
MALT lymphoma and Gastric Cancer
Probiotics for H. pylori
Improve eradication with other anti-therapies and decrease antibiotic related side effects
Mechanisms that treat H. pylori
(1) AM substance production
(2) Epithelial cell adhesion and competition
(3) Mucosal barrier stabilization
(4) IR regulation
(5) sIgA secretion
AM substance production to treat H. pylori
Bifidobacterium and Enterococcus generate heat stable protein
Mucosal barrier stabilization
Tight junction strengthened so pathogen cannot get through
Immune response regulation for H. pylori
Probiotics stimulate –> pathogen gets there –> quick IR to clear
First line of tolerance
sIgA Secretion
For H. pylori treatment
Combo of probiotics more effective in eradication or big proportion elimination
Necrotizing Enterocolitis (NEC)
Acute inflammation due to immature intestine that effects 5-10% of low birth rate infants
NEC leads to…
High mortality, heavy complication, invalidating sequelae
Immaturity of Intestinal barrier
Likely major etiological factors of NEC
Probiotics of NEC
Any microbe can invade so any bacteria that can strengthen the intestinal barrier
Most probiotic trials on NEC
Focus on impact of intestinal colonization measured by fecal microbiota composition analysis
Probiotics for NEC
Variety or mix of strains or synbiotics reduce level of pathogenic bacteria and yeast
L. reuteri ATCC 55730
Accelerate GI motility to prevent bacterial overgrowth in NEC
B. lactis SNSM I-33446
Faster decrease of intestinal permeability levels in NEC –> preterm barrier function
Most trials on NEC focus on
Microbiota to determine if it’s the agent of disease
IBS
GI disorder characterised by association between recurrent abdominal pain/discomfort and change in stool consistency and frequency
IBS categories by symptoms in subgroup
Constipation-predominant, Diarrhea-predominant, Mixed type
IBS Cause
Deregulated IR directly related to deterioration of intestinal barrier function
Microbiota in IBS
Debate but microbiota likely involved in disease symptoms
How microbiota contributes to IBS
(1) Altered fermentation
(2) Harmful modulation of enteric sensorimotor function
(3) Impair intestinal barrier function
(4) Sustained Immune activation without macroscopic signs of inflammation
(5) Harmful modulation of the brain-gut axis
IBS symptom score probiotics
Those that increase barrier function