Topic 5: Prenatal Maternal Stress, diet, and Gut Microbiome Flashcards
what is the recommended intake of folate prior to conception and up to 12th week of pregnancy
400micrograms/day
what is the main period of fetal growth?
during the second and third trimester
what should a pregnant person lower their consumption of?
salt, caffeine
what should a pregnant person not consume
alcohol, soft cheeses, raw fish
list some possible adverse effects of inadequate supply of macro and micronutrients during pregnancy?
premature birth, neurodevelopmental defects (neural tube, cognitive, and motor), even death
what is fetal programming
whereby the fetus senses, receives and responds to intrauterine environment
besides alterations during embryo/fetal brain development, what other period is critical to optimal brain function and connectivity?
the postnatal period, early post natal environment
what are gut bacteria essential for?
metabolism, immunity, well-being, brain development
what is the estimated ratio of bacteria to human cells in the body?
1:1
what is personalized nutrition?
aims to utilize interindividual host and microbiome variations in generating data-driven personalized dietary recommendations.
how is the maternal microbiome gut brain axis altered in stress and anxiety states
increased permeability, decreases richness, increased pro inflammatory cytokines, altered tryptophan metabolism
are you more likely to be breast fed by a low stressed mom than a high stressed mom?
yes
what gut microbiome agents offer safe and effective ways to improve microbiome?
pre and probiotics
clinical studies on maternal probiotic administration?
GDM, PE, infant allergy, infant weight gain, maternal GI, vaginal infections
preclinical studies on maternal probiotic admin
protects hypertension in offspring, lipid profile, immune system, microbiota
clinical studies on maternal prebiotic admin
maternal microbiota
preclinical studies on maternal prebiotic admin
improved weight gain, colon length, increased muscle mass, decreased allergies
what are psychobiotics?
psychobiotics are beneficial bacteria (probiotics) or support for such bacteria (prebiotics) that influence bacteria-brain relationships
example of probiotic
LGG
Example of prebiotcs
galactooligosaccarides (GOS)
what does the prebiotic GOS do?
supports and encourages the growth of these beneficial bacteria in the gut that are already present, such as bifidobacterium and lactobacillus, which are linked to emotional well-being. offer broader and more stable microbiome changes than probiotics, pregnancy/personal commensal composition is enhanced, not modified, hence safer and more acceptable.
compare newborn brain size to adult brain size and first postnatal year brain’s size to adult brain size
newborn brain is 36% size of adult brain
1yo brain is 72% size of an adult brain
what is responsible for the rapid increase in brain size during the first year?
due to rapid increase in neuropril (dendrites, synapses, axons)
what occurs during adolescence?
remodelling and myelination of neural circuits
what does experience in postnatal development shape
postnatal environment shapes the brain connectivity and circuitry
what do prenatal brain growth disorders arise from
disruptions to neuronal progenitor pool size, neuronal progenitor cell proliferation versus division, neuronal migration, DNA damage response and repair
what do postnatal brain disorders mainly arise from?
neuronal arborization, spinogenesis, synaptogenesis, remodeling, gliogenesis, myelination, neurodegeneration
what is a cause of post natal brain growth disorders?
neurodegeneration
what is the stress hyporesponsive period?
naturally lower levels of stress hormone, less stress/reactivity to stressors,
examples of early life stress
exposure to infection, maternal deprivation/separation, and substance use disrupts the programmed development
what does exposure to early-life stressors yield?
a myriad of deviations in brain circuitry, stress responsivity, cognitive function, microbiome-gut-brain axis, and general health
how long does the stress hyporesponsiveness period last?
5-7 years old in humans, PN day 2-14
what helps to keep infant stress low in animal models?
velocity of strokes and licks to the pup from mother
what is the gut microbiome associated with in early life in terms of brain
brain development, brain function, emotional, cognitive, and motor function
most important in gut microbiome of newborn
bifidobacteria and lactobacillus
how are lactobacillus and bifidobacteria able to colonise the baby’s gut?
vaginal birth
what component of breast milk promotes bifidobacteria?
human milk oligosaccarides
what ways do the microbes in the gut signal to the brain
the neuroendocrine system, the immune system, and neuroactive peptides
what are the two biggest influences on a child’s microbiome
antibiotics and diet
what components of maternal nutrition influence baby
over/undernutrition, vitamin D status, dietary methyl donors, LCPUFA intakes, food pollutants
what are important factors for neonatal and infant nutrition
formula milk, human milk, pre/probiotics
what are the common factors influencing the infants epigenome?
human genome, environmental factors (stress exposure and nutrition)
what influences a baby’s microbiome?
maternal microbiota, mode of delivery, maternal and infant diet, antenatal and postnatal antibiotic exposure, urban/rural environment
give examples of effects of microbiome and brain development in germ-free mice?
synaptic and neural plasticity increased, decreased BDNF in areas lie the amygdala, cortex and hippocampus, immature microglia, increased microglia, increased neurogenesis in hippocampus, increased volume in the amygdala and hippocampus, increased BBB permeability, decreased tight junction protein expression
in germ free mice, what is reduced?
connections and branching in axons is reduced
how does stress in early postnatal life affect gut brain axis?
altered microbiome gut-brain access
in animal models of stress during postnatal period, how do microbiota-targeted interventions impact the altered gut-brain axis?
reduce visceral pain, antidepressant-like beahviour, reduced stress response, microbiota composition and diversity, spinal cord pathways changed
how do pre/probiotics or combo of both improve neurological complications?
increasing the production of SCFA, neurochemicals, reducing gut permeability, and modulating the gut microbial composition, immune, metabolic, and neural properties
what needs to be taken into account for results of pre/probiotics in studies, variance between individuals?
different host baseline: gender, metabolism, age
what kind of diversity do babies need?
decreased microbiome diversity
what bacteria predominate a breastfed baby’s gut?
bifidobacteria
what is observed in formula-fed babies?
more complex microbiome
what component of breast milk leads to promotion of bifidobacteria dominance?
HMOs
what are features of bifidobacteria predominance?
leads to reduced pH of the intestine
inhibits growth of pathogenic bacteria
indirectly increase short chain fatty acid production, provides energy for enterocytes and are key molecules for maintaining intestinal health
associated with optimal development of stress system and brain
what does decreased intestinal pH reduce the risk of?
necrotizing colitis
describe human breast milk microbiome
has its own microbiome, and is beneficial for the neonatal gut microbiome
what is Milk Fat goluble membrane
component of breast milk, now supplemented in baby formula
what was observed in infants fed MFGM in formula
infants fed MFGM supplemented formula showed improved cognitive functioning compared to those fed standard formula, it was comparable to those who were breast fed
MFGM and visceral sensitivtiy?
MFGM supplemented formula reduced visceral sensitivity
how does MFGM improve visceral sensitivity
it increases the threshold of both control groups and stressed(maternally separated)
why does our gut microbiome change over time?
our microbiota changes over time due to the demands on our body at that time
