Gut Health — Fundamentals

The Gut Microbiome

Your gut contains 38 trillion bacteria — more than your body's cells
They play roles in: digestion, immunity (70% of immune system is in gut),
                    mood (90% of serotonin made in gut), weight regulation

Diversity is key: more species = better health
Modern lifestyle reduces diversity: processed food, antibiotics, stress

Signs of poor gut health:
  Bloating, gas, constipation or diarrhea
  Frequent illness (low immunity)
  Fatigue, brain fog
  Skin issues (acne, eczema)
  Food sensitivities
  Mood problems (anxiety, depression)

Feeding Your Gut

Prebiotics (feed good bacteria):
  Fiber-rich foods: onion, garlic, leeks, banana, oats, lentils
  Goal: 30+ different plant foods per week (diversity)
  
Probiotics (live beneficial bacteria):
  Fermented foods: yogurt (dahi), kefir, kimchi, sauerkraut, kombucha
  Look for: "live and active cultures" on label
  Probiotic supplements: useful during/after antibiotics
  
Diverse plant diet:
  Each plant feeds different bacteria
  "Eat the rainbow" — different colors = different phytonutrients
  Whole grains > refined grains (retain fiber)

What harms gut bacteria:
  Ultra-processed food (emulsifiers, artificial sweeteners)
  Antibiotics (necessary sometimes, but kill good bacteria too)
  Chronic stress (gut-brain axis — stress disrupts microbiome)
  Excessive alcohol
  Sedentary lifestyle

Digestive Health

Common issues:
  IBS (Irritable Bowel Syndrome): cramping, bloating, altered bowel habits
    Management: Low-FODMAP diet, stress reduction, probiotics, fiber
  
  Acid reflux / GERD: stomach acid backs up into esophagus
    Causes: large meals, lying down after eating, spicy food, obesity
    Help: eat smaller meals, wait 2-3h before lying down, avoid triggers
  
  Constipation:
    Increase fiber gradually (sudden increase = more gas)
    Drink more water (fiber needs water to work)
    Exercise (stimulates gut motility)
    Don't ignore urge to go

When to see a doctor:
  Blood in stool, unexplained weight loss
  Symptoms lasting >2 weeks or significantly affecting life
  Family history of colorectal cancer