9 Signs You Have Leaky Gut.
Even If Your Doctor Said It Isn't Real.

Sign 1 — Bloating

Bloating that builds through the day regardless of what you ate.

Gut bacteria shed LPS endotoxins continuously. In an intact gut wall, this stays contained. In a permeable wall, it crosses into your bloodstream all day. Your immune system responds with inflammation that compounds through every hour. By 7pm it looks like you're six months pregnant — not from the food, but from twelve hours of accumulated gut-derived inflammation.

Sign 2 — Brain fog

Cognitive fatigue that sleep doesn't fix.

LPS bacterial endotoxins that cross a permeable gut wall can reach the blood-brain barrier. The neuroinflammation that follows presents as reduced processing speed and the specific foggy, underwater quality people with gut problems describe. If your brain fog is worse on bad gut days, this is the mechanism.

Sign 3 — Skin

Acne, eczema, or rosacea that no topical treatment resolves.

Your skin is downstream of your gut. LPS crossing the gut wall stimulates mast cells in the skin to release histamine and inflammatory cytokines. If skin problems co-exist with gut symptoms and persist despite topical treatment, the gut wall is generating what the skin is displaying. No cleanser addresses a systemic source.

Sign 4 — Fatigue

Fatigue that rest doesn't fix.

Chronic gut permeability drives a sustained low-grade inflammatory state that is metabolically expensive. Your immune system in permanent activation consumes energy. Eight hours of sleep, still waking depleted — this is immune-driven metabolic drain originating at the gut wall, not a sleep problem.

Sign 5 — Allergies getting worse

Seasonal allergies worsening on the same medication, year on year.

70% of your immune cells live in your gut. Gut wall damage creates chronic LPS-driven immune activation that lowers your histamine threshold year by year. The antihistamine hasn't changed. The immune baseline it's working against has. The war is in the gut, not the airways.

Sign 6 — Growing food sensitivities

A food sensitivity list that keeps expanding.

Gut wall damage allows undigested food particles into systemic circulation. Your immune system mounts a response. You develop a new sensitivity. Eliminate that food — the list grows again. The wall is continuously sensitising your immune system to new antigens. Eliminating foods treats the result, not the cause.

Sign 7 — Hormonal disruption

Worsening PMS, irregular cycles, hormonal symptoms that track with gut flares.

Your liver processes hormones and receives blood directly from your gut. When gut permeability floods that blood with LPS and inflammatory compounds, the liver's detoxification capacity is impaired. Oestrogen accumulates. If gut symptoms and hormonal symptoms worsen together, the gut-liver-hormone connection is operative.

Sign 8 — Joint pain without diagnosis

Joint pain with no structural cause on imaging.

LPS endotoxins crossing the gut wall reach joint tissue through systemic circulation, producing localised inflammation that presents like arthritis but has no structural cause. Common in people with leaky gut. Almost never identified as gut-related by the rheumatologist examining the joint.

Sign 9 — Autoimmunity onset after gut disruption

An autoimmune condition that began within months of an antibiotic course, GI illness, or period of extreme stress.

Dr. Fasano's research demonstrates increased intestinal permeability precedes the onset of multiple autoimmune conditions — including Hashimoto's, rheumatoid arthritis, and MS. If the timeline fits, the mechanism is consistent with the gut permeability pathway.