Gut Microbiota, Digestion, and Gastrointestinal Disorders Overview

what three things collectively make up the gut microbiota

bacteria, viruses, micro-organisms

diet

has direct effects on human health as well as indirect effects mediated by the gut microbiome

probiotics

in foods like yogurt, help ease GI issues

prebiotics

feed probiotics which produce short-chain fatty acids that support digestion and health (fiber)

gut dysbiosis

microbiome imbalance that may promote an outbreak of harmful pathogens or increase risk for chronic disease

gut-brain axis

two way communication between the brain and GI tract; brain signals to Gi to regulate muscle movement and enzyme secretion; Gi signal to brain for fermentation

IBS (irritable bowl syndrom)

recurring abdominal/rectal pain related to defecation

IBS symotoms

gas, bloating, diarrhea, constipation

lifestyle modifications for people with IBS

diet can help

villi and micro-villi

facilitates nutrient absorption, increases the surface area in the small intestine so it can give the nutrients more chances to absorb

the three types of transport

simple diffusion, facilitated diffusion, active transport

simple diffusion

molecules can pass through cell membrane with no help

facilitated diffusion

has to be recognized by a protein carrier and the nutrient is transported out the other side

active transport

protein carrier and has to use ATP to get the nutrient across

lymphatic system

lipids and fat soluble vitamins, transport system in between cells; after, molecules get dumped into bloodstream for organs to use

last organ to get access to nutrients after the lymphatic system

liver

hepatic portal vein

vein that goes directly to the liver, liver takes what it needs and what is left over goes to the bloodstream to other organs

vascular system

closed system of vessels where your blood is flowing, heart serves as the pump

GERD (gastroesophageal reflux disease)

really bad heartburn, lower esophageal sphincter loses tone and lets acid reflux into esophagus from stomach

trigger foods for GERD

acidic foods, tomatoes, coffee, fatty/fried foods

risk factor for GERD

extra weight around the sphincter, a lot of tummy fat

GERD treatment

antacids, acid controller, proton pump inhibitor (PPIs)

diarrhea

frequent, loose, watery poop

diarrhea causes

IBS, colitis or crohn's disease, foodborne illness

diarrhea management

drink fluids, medical help if persistent past 24-48 hours, if chronic some forms of fiber

constipation

hard and dry stool less than 3 times per week

constipation treatment

increase fiber and fluids slowly, increase physical activity, probiotics (limited evidence)

calcium supplements make constipation worse/better

worse

lactose intolerance

can't digest lactose due to no lactase enzyme production

lactose intolerance impacts what percent of the world population

65%

celiac disease

autoimmune disorder where gluten triggers inflammation and damage of the small intestine

gluten is a

protein

gluten is found in what grains

wheat, barley, and rye

diverticulosis

intestine walls weaken and bulge

diverticula

forming pockets

diverticulites

the pockets get infected

long term goal of diverticulitis

increase fiber gradually

digestion

the physical and chemical breakdown of food into nutrients that can be absorbed

absorption

occurs after digestion, the process of moving nutrients from the digestive system into the body's circulation

cirrculation

the transportation and distribution of nutrients throughout the body for immediate usage or storage

digestive tract organs (GI tract)

mouth, esophagus, stomach, small intestine, large intestine, rectum

purpose of accessory organs

secrete molecules into the digestive tract organs to aid in digestion

the accessory organs are

liver, pancreas, gall bladder

what happens in the mouth

mastication (chewing)

salivary grands produce what two enzymes

salivary amylase and lingual lipase

salivary amylase

break down big CHO

lingual lipase

break down big lipids

what is behind your pharynx in your mouth

trachea and esophagus

what covers the trachea so you don't choke

epiglottis

enzyme

a protein that helps a chemical reaction happen

digestive enzyme

break molecules down chemically

hormone

a protein that tells other molecules what to do, tells enzymes to speed up/slow down

are lipids and fats water soluable

no

what has to surround lipids and fats so they can be broken down

bile

what enzymes/hormones does the liver produce

bile

what enzymes/hormones are stored in the gall bladder

bile

purpose of bile

surround lipids in chyme so they can break into smaller pieces (emulsification) and help them be more water soluble so enzymes can break them down

digestion occurring in the esophagus

segmentation (breaking chyme into smaller pieces), peristalsis

what prevents back flow and acid reflux from the stomach

lower esophageal sphinter

digestion occurring in the stomach

three sets of muscles, further mix bolus of food and fluids to produce chyme

enzymes/hormones produced by the stomach

gastrin which then releases hydrochloric acid which then releases pepsin, gastric lipase, intrinsic factor

what does gastric lipase do

digest large fat molecules into smaller one

what does intrinsic factor do

binds to vitamin b12 and facilitates absorption of it

what does gastrin do

tell your stomach cells to release hydrochloric acid

what does hydrochloric acid do in the stomach

drops the pH of your stomach to be very acidic and activates an enzyme called pepsin

what does pepsin do

break down proteins into amino acids to be absorbed

digestion in the small intestine

absorption and segmentation

enzymes/hormones produced in the small intestine

CKK, secretin, lactase, maltase, sucrase, peptidases

produced in the liver but used in the small intestine

bile

secretin

hormone that tells pancreas to secrete bicarbonate

lactase/maltase/sucrase

break down molecules with 2 CHO to ones with 1 CHO

peptidases

break down molecules with 4-10 amino acids to 1-2 amino acids

cholecystokinin (CKK)

hormone that tells the pancreas to make enzymes and tells gall bladder to release bile into the small intestine

large intestine digestion

small amount of absorption, fecal matter made and moved

pancreas

secretes enzymes into small intestine

enzymes produced in the pancreas

pancreatic amylase, pancreatic lipase, bicarbonate, proteases

what does pancreatic amylase do

breaks down large CHO

what does pancreatic lipase do

break down large lipids into fatty acids

what does proteases do

break down protein into amino acids

what does bicarbonate do

base to neutralize chyme from super acidic stomach

the sections of the small intestine in order

duodenum, jejunum, ileum

how long is the duodenum

10 inches

how long is the jejunum

8 feet

how long is the ileum

12 feet

how long is the large intestine (colon)

3.5 feet