M5-L2 Flashcards by Black Women

Which of the following is NOT listed as a factor that can contribute to dysbiosis?

A. Excessive or inappropriate use of antibiotics
B. Frequent use of antacids
C. Increased intake of sugar or protein
D. Regular physical exercise

D. Regular physical exercise

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Exposure to which combination of factors is associated with the development of dysbiosis?

A. Chronic stress, artificial sweeteners, and pesticide exposure
B. High fiber intake, probiotics, and reduced alcohol consumption
C. Increased sleep duration and low protein intake
D. Vitamin supplementation and balanced nutrition

A. Chronic stress, artificial sweeteners, and pesticide exposure

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Exposure to which combination of factors is associated with the development of dysbiosis?

A)Poor dental hygiene
B) anxiety
C) both a and b
D)Vitamin supplementation

C) both a and b

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The gut–brain axis is best defined as:

A. Unidirectional signaling from the brain to the gut
B. Communication between the enteric nervous system only
C. Bidirectional communication between the central nervous system and gut microbiota
D. Hormonal signaling limited to the digestive tract

C. Bidirectional communication between the central nervous system and gut microbiota

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Which of the following substances released from the gut can signal to the brain?

A. Hormones, neurotransmitters, and immunological factors
B. Digestive enzymes only
C. Bile salts and fatty acids only
D. Vitamins and minerals only

A. Hormones, neurotransmitters, and immunological factors

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Signals from the gut to the brain may reach the CNS:

A. Only through the bloodstream
B. Only through the vagus nerve
C. Directly or via autonomic neurons
D. Only through immune cells

C. Directly or via autonomic neurons

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Which of the following functions is regulated by the vagus nerve?

A. Voluntary skeletal muscle movement
B. Regulation of digestion, heart rate, and respiratory rate
C. Visual and auditory processing
D. Thermoregulation via brown adipose tissue

B. Regulation of digestion, heart rate, and respiratory rate

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Which reflex action is mediated by the vagus nerve?

A. Pupillary light reflex
B. Knee-jerk reflex
C. Swallowing
D. Stretch reflex

C. Swallowing

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What evidence supports the role of the vagus nerve in microbiota–brain communication?

A. Increased immune signaling in germ-free mice
B. Neurochemical and behavioral effects persisted after vagotomy
C. Neurochemical and behavioral effects were absent in vagotomized mice
D. Microbiota signals bypass the nervous system

C. Neurochemical and behavioral effects were absent in vagotomized mice

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The gut–brain connection involves chemicals called neurotransmitters that primarily regulate:

A. Digestion and nutrient absorption
B. Immune cell differentiation
C. Feelings and emotions
D. Blood pressure and heart rate

C. Feelings and emotions

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Which statement about neurotransmitter production is correct?

A. Neurotransmitters are produced only in the brain
B. Gut cells and microbes can produce neurotransmitters
C. Only immune cells produce neurotransmitters
D. Neurotransmitters are produced exclusively by neurons

B. Gut cells and microbes can produce neurotransmitters

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A large proportion of which neurotransmitter is produced in the gut?

A. Dopamine
B. GABA
C. Serotonin
D. Norepinephrine

C. Serotonin

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Gamma-aminobutyric acid (GABA) is primarily involved in regulating:

A. Appetite and digestion
B. Fear and anxiety
C. Motor coordination
D. Sleep–wake cycles

B. Fear and anxiety

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Studies in mice show that probiotics such as Lactobacillus and Bifidobacterium can:

A. Eliminate serotonin production
B. Decrease GABA production
C. Increase GABA production and reduce anxiety- and depression-like behavior
D. Increase stress hormone secretion

C. Increase GABA production and reduce anxiety- and depression-like behavior

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Which function of the gut–brain axis involves regulation of peristalsis and enzyme secretion?

A. Cognitive function
B. Energy homeostasis
C. Digestion and motility
D. Immune modulation

C. Digestion and motility

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The gut–brain axis helps maintain energy homeostasis by regulating:

A. Blood oxygen levels and ventilation
B. Hunger, satiety, food preferences, and metabolism
C. Electrolyte balance only
D. Circadian rhythms

B. Hunger, satiety, food preferences, and metabolism

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Gut microbiota can influence the body’s stress response primarily through which system?

A. Renin–angiotensin system
B. Sympathetic–adrenal–medullary axis
C. Hypothalamic–pituitary–adrenal (HPA) axis
D. Parasympathetic reflex arcs

C. Hypothalamic–pituitary–adrenal (HPA) axis

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Dysbiosis of the gut microbiota has been associated with changes in:

A. Vision and hearing
B. Mood, anxiety, depression, and pain sensitivity
C. Muscle strength only
D. Bone density

B. Mood, anxiety, depression, and pain sensitivity

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Chronic gut-driven inflammation may impact brain function and contribute to:

A. Improved memory formation
B. Neurodegenerative disorders
C. Increased synaptic plasticity
D. Reduced immune surveillance

B. Neurodegenerative disorders

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Which cognitive processes are influenced by gut microbiota and their metabolites?

A. Reflexes only
B. Brain development, learning, memory, and synaptic plasticity
C. Motor neuron firing rates exclusively
D. Visual acuity

B. Brain development, learning, memory, and synaptic plasticity

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Functions of SCFAc:Acetate

Most Abundant and Systemic SCFA

Energy and Lipid Metabolism: muscle brain and hear

Appetite and Metabolic Regulation- stimulates hormones like GLP-1 and PYY

Cross-Talk With the Brain- influences hypothalamic control of appetite and neurotransmitter balance.

Immune Modulation- Promotes regulatory T cell (Treg) development and suppresses pro-inflammatory cytokine release

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Propionate

Gluconeogenic and Immune-Modulating SCFA

Liver Gluconeogenesis- serves as a substrate for glucose production in liver

Lipid and Cholesterol Regulation Inhibits hepatic cholesterol synthesis

Immune and Inflammatory Control- suppresses inflammation, enhances Treg differentiation, and balances Th17/Treg responses.

Gut–Brain Communication Activates vagal afferents and modulates serotonin and dopamine signaling.

Can influence satiety and energy balance through gut hormone release.

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Butyrate

Colon’s Primary Fuel and Barrier Protector

Energy Source for Colonocytes- supports epithelial integrity and oxygen balance (reducing inflammation-prone conditions).

Maintaining Gut Barrier Integrity- Strengthens tight junction proteins → prevents “leaky gut.”

Anti-inflammatory and Epigenetic Regulation Inhibits histone deacetylases (HDACs) → affects gene expression.

Promotes Treg cell expansion and reduces pro-inflammatory cytokines.

Neuroprotective and Mood Effects - modulates microglial activity and neurotrophic factors (like BDNF).
Linked to reduced anxiety- and depression-like behaviors in animal models

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Lipopolysaccharide (LPS) is best described as:

A. A neurotransmitter produced by gut microbes
B. A hormone secreted by intestinal cells
C. An inflammatory toxin produced by certain bacteria
D. An anti-inflammatory metabolite

C. An inflammatory toxin produced by certain bacteria

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Elevated circulating plasma LPS levels have been linked to which phenotype in both human and rodent studies? A. Lean phenotype B. Athletic phenotype C. Obese phenotype D. Aging phenotype

C. Obese phenotype

High circulating LPS and inflammation have been associated with which of the following brain disorders? A. Parkinson’s disease only B. Severe depression, dementia, and schizophrenia C. Epilepsy and migraine D. Autism spectrum disorder exclusively

B. Severe depression, dementia, and schizophrenia

Compared to lean individuals, obesity is associated with which change in the gut microbiota? A. Increased bacterial diversity and increased fecal microbial gene richness B. No change in bacterial diversity or gene richness C. Decreased bacterial diversity and decreased fecal microbial gene richness D. Decreased bacterial diversity with increased fecal microbial gene richness

C. Decreased bacterial diversity and decreased fecal microbial gene richness

hich statement best describes the relationship between gut dysbiosis and obesity? A. Gut dysbiosis has no role in obesity B. The contribution of gut dysbiosis to obesity is well established, but mechanisms are not fully defined C. Gut dysbiosis only affects lean individuals D. The mechanisms linking gut dysbiosis to obesity are fully understood

B. The contribution of gut dysbiosis to obesity is well established, but mechanisms are not fully defined

Diet influences the gut microbiome primarily by: A. Preventing microbial colonization B. Acting as a major manipulator of microbial composition C. Eliminating bacterial diversity entirely D. Affecting only viral populations

B. Acting as a major manipulator of microbial composition

Feeding a high-fat diet (HFD) is associated with which outcome? A. Improved metabolic health and insulin sensitivity B. Microbiome dysbiosis occurring alongside metabolic abnormalities leading to obesity and type 2 diabetes C. Increased microbial diversity and reduced inflammation D. Reduced energy storage and weight loss

B. Microbiome dysbiosis occurring alongside metabolic abnormalities leading to obesity and type 2 diabetes

Which gut microbiota pattern is associated with obesity (and similarly observed during pregnancy)? A. Increased Bacteroidetes and decreased Firmicutes B. Decreased Bacteroidetes and increased Firmicutes C. Increased proportions of both Bacteroidetes and Firmicutes D. No change in Bacteroidetes or Firmicutes proportions

A. Increased Bacteroidetes and decreased Firmicutes

Which gut microbiota change is associated with increased energy harvest from the diet? A. Increased Bacteroidetes and decreased Firmicutes B. Reduced Bacteroidetes and increased Firmicutes C. Increased Proteobacteria only D. No change in microbial composition

B. Reduced Bacteroidetes and increased Firmicutes

Gut dysbiosis contributes to obesity in part by promoting: A. Acute systemic inflammation B. Localized intestinal inflammation only C. Chronic low-grade systemic inflammation D. Anti-inflammatory immune responses

C. Chronic low-grade systemic inflammation

Altered appetite regulation associated with dysbiosis is primarily linked to changes in: A. Digestive enzyme secretion B. Neurotransmitter production C. Oxygen availability D. Electrolyte balance

B. Neurotransmitter production

Gut microbes can increase adiposity by: A. Reducing host gene expression B. Altering host genes and hormone secretion that regulate fat storage C. Inhibiting lipid absorption entirely D. Decreasing insulin signaling

B. Altering host genes and hormone secretion that regulate fat storage

Dysbiosis affects host metabolism through altered production of which metabolites? A. Amino acids and vitamins B. Neurotransmitters only C. Short-chain fatty acids (SCFAs) and bile acids D. Steroid hormones

C. Short-chain fatty acids (SCFAs) and bile acids

Which observation supports the idea that antibiotic use can influence body weight? A. Antibiotics selectively kill only pathogenic bacteria B. Antibiotics have no effect on gut microbiota C. Mice treated with antibiotics gained weight, and antibiotics added to animal feed promote growth D. Antibiotics reduce growth rates in livestock

C. Mice treated with antibiotics gained weight, and antibiotics added to animal feed promote growth

Which statement about Helicobacter pylori is supported by the evidence provided? A. It increases the risk of asthma and allergies B. It is always pathogenic and should be eliminated C. Its loss may be associated with acid reflux and increased asthma/allergy risk D. It has no interaction with the immune system

C. Its loss may be associated with acid reflux and increased asthma/allergy risk

In many COVID-19 patients, which combination of symptoms and changes has been observed? A. Respiratory symptoms only with increased gut microbial diversity B. Gastrointestinal complications with loss of commensal gut microbes C. Neurological symptoms without microbiome changes D. Increased commensal microbes and reduced inflammation

B. Gastrointestinal complications with loss of commensal gut microbes

Commensal gut microbes primarily protect the host by: A. Producing viral particles B. Directly preventing invasion and colonization by pathogenic microbes C. Digesting dietary fiber only D. Increasing gut permeability

B. Directly preventing invasion and colonization by pathogenic microbes

What change in the gut microbiome was observed within one week of COVID-19 infection? A. Increased alpha diversity B. Reduced beta diversity C. Reduced alpha diversity D. No measurable change

C. Reduced alpha diversity

Gut microbiota dysbiosis is closely linked to which inflammatory bowel diseases? A. Irritable bowel syndrome and celiac disease B. Crohn’s disease and ulcerative colitis C. Gastritis and peptic ulcer disease D. Appendicitis and diverticulitis

B. Crohn’s disease and ulcerative colitis

In inflammatory bowel disease (IBD), dysbiosis primarily contributes to disease progression by: A. Reducing gut motility B. Triggering local intestinal inflammation C. Increasing nutrient absorption D. Suppressing immune responses

B. Triggering local intestinal inflammation

Irritable bowel syndrome (IBS) is best described as: A. A chronic inflammatory disease of the gut B. A functional gastrointestinal disorder associated with dysbiosis C. An autoimmune disorder targeting the colon D. An infectious gastrointestinal disease

B. A functional gastrointestinal disorder associated with dysbiosis

Compared with ulcerative colitis (UC), Crohn’s disease (CD) is characterized by which gut microbiota pattern? A. Greater microbial diversity and increased community stability B. Similar levels of dysbiosis with no distinct microbial features C. More severe dysbiosis with reduced diversity, a less stable microbial community, and a specific microbial signature D. Reduced dysbiosis and absence of disease-specific microbial groups

C. More severe dysbiosis with reduced diversity, a less stable microbial community, and a specific microbial signature

Which factor can act as an initial environmental trigger in the development of IBD-related dysbiosis? A. Genetic mutation only B. Infection, diet, or antibiotics C. Neurotransmitter imbalance D. Reduced gut motility

B. Infection, diet, or antibiotics

Following an environmental trigger, the next key step in the IBD feedback loop is: A. Immune tolerance restoration B. Microbial imbalance (dysbiosis) C. Cytokine clearance D. Resolution of inflammation

B. Microbial imbalance (dysbiosis)

Dysbiosis in IBD contributes to disease progression primarily by causing: A. Increased nutrient absorption B. Loss of immune activation C. Loss of tolerance and epithelial barrier damage D. Enhanced mucus production

C. Loss of tolerance and epithelial barrier damage

Which immune components are prominently activated during IBD-associated inflammation? A. Th2 cells and eosinophils B. Th1/Th17 cells, macrophages, and cytokines C. B cells and antibodies only D. Regulatory T cells exclusively

B. Th1/Th17 cells, macrophages, and cytokines

Why is IBD considered a vicious cycle of chronic inflammation? A. Inflammation permanently eliminates gut microbes B. Immune activation resolves dysbiosis C. Inflammation alters the gut environment, promoting further dysbiosis D. Dysbiosis occurs only once at disease onset

C. Inflammation alters the gut environment, promoting further dysbiosis

The hygiene hypothesis proposes that: A. Increased exposure to microbes in early life increases autoimmune disease risk B. Lack of early microbial exposure reduces tolerance of the adaptive immune response C. Adaptive immunity develops independently of microbial exposure D. Immune tolerance is determined solely by genetics

B. Lack of early microbial exposure reduces tolerance of the adaptive immune response

Which factors are thought to contribute to the hygiene hypothesis? A. Increased physical activity and rural living B. Cleaner living conditions, urbanization, and increased antibiotic use C. Reduced vaccination rates D. Increased exposure to parasites only

B. Cleaner living conditions, urbanization, and increased antibiotic use

Probiotics are best defined as: A. Non-digestible fibers that feed gut bacteria B. Live bacteria that provide health benefits when consumed C. Antibiotics that selectively kill harmful microbes D. Hormones produced by gut microbes

B. Live bacteria that provide health benefits when consumed

Which statement correctly describes probiotics and mental health? A. All probiotics have identical effects on mental health B. Probiotics have no effect on stress or mood C. Some probiotics have been shown to improve stress, anxiety, and depression symptoms D. Probiotics only affect digestion

C. Some probiotics have been shown to improve stress, anxiety, and depression symptoms

Prebiotics primarily influence gut and brain health by: A. Acting as live bacteria B. Directly killing pathogenic microbes C. Being fermented by gut bacteria D. Inhibiting neurotransmitter release

C. Being fermented by gut bacteria

Supplementation with the prebiotic galactooligosaccharides was associated with which outcome? A. Increased cortisol levels B. No change in stress hormones C. Reduced stress-related cortisol levels D. Increased anxiety symptoms

C. Reduced stress-related cortisol levels

Why do many orally consumed probiotics fail to reach the colon alive? A. They are rapidly absorbed in the stomach B. They are destroyed by gastric acid, digestive enzymes, and microbial competition C. They cannot survive body temperature D. They are eliminated by immune cells in the mouth

B. They are destroyed by gastric acid, digestive enzymes, and microbial competition

Approximately what proportion of orally consumed probiotic bacteria survive passage through the stomach and small intestine? A. >90% B. 50–70% C. 10–30% D. <1%

C. 10–30%

Which statement best explains why probiotic effects are inconsistent? A. All probiotics behave identically B. Benefits are strain-specific, not generalizable to species or genus C. Only fermented foods contain viable probiotics D. Probiotics permanently colonize all hosts

B. Benefits are strain-specific, not generalizable to species or genus

Probiotics are most likely to colonize the gut in which individuals? A. Healthy individuals with stable microbiota B. Individuals after antibiotic use or illness C. Individuals on high-fat diets D. Individuals with rapid gut motility

B. Individuals after antibiotic use or illness

Even when probiotics do not permanently colonize the gut, they can still: A. Have no biological effect B. Permanently alter host DNA C. Modulate immune signaling, inhibit pathogens, and enhance barrier integrity D. Replace the native microbiota

C. Modulate immune signaling, inhibit pathogens, and enhance barrier integrity

Which factor presents the greatest initial barrier to probiotic survival after ingestion? A. Competition in the colon B. Gastric acid with a pH of 1.5–3.5 C. Immune cell phagocytosis D. Lack of nutrients in the stomach

B. Gastric acid with a pH of 1.5–3.5

Which delivery method most improves probiotic survival through the GI tract? A. Powdered supplements B. Liquid formulations C. Microencapsulation or enteric-coated capsules D. Chewable tablets

C. Microencapsulation or enteric-coated capsules

Synbiotics enhance probiotic effectiveness by: A. Eliminating pathogenic bacteria B. Combining probiotics with fibers that feed them C. Increasing stomach acid resistance D. Suppressing immune responses

B. Combining probiotics with fibers that feed them

M5-L2 Flashcards

(65 cards)