Your Anxiety Is a Fire in Your Gut | The Angry Gut, Chapter 1

Inflammation and anxiety · blood tests

Can Inflammation Cause Anxiety? What Blood Work and Testing Show

Inflammation can contribute to anxiety in a subset of people, not in everyone. That subset only shows up when someone measures, starting with inflammatory blood markers such as C-reactive protein chosen with your physician.

Anxiety is usually treated as a problem inside the skull. A growing set of experiments says some of it is lit lower down, and part of that fire leaves marks in ordinary blood work.

Can inflammation cause anxiety? In a subset of people the evidence says it can contribute, and that subset only shows up when someone measures. Dr. Padda’s video Your Anxiety Is a Fire in Your Gut argues that the gut, the first brain, can inflame the second brain in your skull. Measura [Cardiometabolic and Autonomic Health Analysis] asks the practical follow-up: what in your own numbers would show whether that argument applies to you?

Can inflammation change your mood?

The strongest human evidence is experimental. Healthy volunteers given a small dose of bacterial endotoxin, a fragment of the outer coat of gut bacteria, develop lower mood under placebo-controlled conditions. In a trial of one hundred and fifteen healthy adults randomized to endotoxin or saline, the people whose mood fell furthest already carried more perceived stress, more sensitivity to feeling socially cut off and more baseline anxiety. Their inflammatory chemicals did not rise any higher than everyone else’s. What differed was the size of the response.

Hepatitis C clinics watched the same thing for two decades. Interferon, an inflammatory messenger given as treatment, brought on major depression in roughly one patient in four by 24 weeks, more often in people with a prior depressive episode or higher baseline interleukin-6.

Can the gut trigger anxiety?

Anxiety-like behavior has been produced from the gut lining itself. In mice, switching on enterochromaffin cells, the serotonin-releasing cells of the intestinal lining, made the gut hypersensitive and triggered anxiety-like behavior that settled once serotonin signaling was blocked. No serotonin had to reach the brain, and it could not have: although roughly 90 to 95 percent of all serotonin in the body is made in the gut, that supply does not cross the blood-brain barrier. The message travels on nerves, and through inflammation, which steers tryptophan away from the brain’s own serotonin supply.

Dr. Padda admits he used to give patients the simpler story, that a gut making serotonin must be running their mood. The manufacturing half held up. The delivery half did not, and correcting it is what points toward inflammation as the link that can actually be measured.

The wall of the first brain also answers to how people live. In healthy married couples, more hostile arguments went with more of a blood marker for bacterial fragments crossing the gut wall, and that marker tracked whole-body inflammation: 79 percent of people in its highest group had an average daytime CRP above 3, against 21 percent in its lowest. A food supply built on flour and sugar, stripped of fermentable fiber, adds fuel from the plate. Across The Angry Gut, that combined terrain goes by one name, metaflammation.

Does inflammation cause anxiety in everyone?

Inflammation does not explain everyone. Across 30 studies of people with depression, 27 percent had a C-reactive protein, or CRP, above 3 mg/L, the usual line for low-grade inflammation; at a cutoff of 1 mg/L the share was 58 percent. Those figures come from depression research rather than anxiety research, but the shape is the point: an inflamed minority exists, and nobody can see it without a blood draw. In one treatment trial, an antibody that blocks an inflammatory signal helped depressed patients only when their CRP sat above 5 mg/L.

What does a routine anxiety visit miss?

Anxiety is usually assessed with a conversation and a questionnaire, while digestive symptoms are sent to a different clinic. CRP and fasting insulin may never be drawn, and when they are, no one may connect them to mood. A stool microbiome report does not close that gap. Large microbiome studies of depression have replicated poorly, and the same bacterial shifts appear across depression, bipolar disorder, schizophrenia and anxiety alike. Measura does not offer stool, breath or microbiome tests.

Which tests show whether inflammation is behind anxiety?

Laboratory panels report metabolic and inflammatory blood markers. Whether CRP and fasting insulin are included is decided with your physician, and one high CRP calls for a repeat, since infection, injury or a hard workout can also push it up.
Bioimpedance body composition separates fat from muscle, the tissue picture that tends to accompany high insulin and a widening waist.
Heart rate variability records beat-to-beat variation in your heart rate, a measure of how the autonomic nervous system is regulating at rest. It describes regulation; it does not diagnose anxiety.

None of these tests diagnoses an anxiety disorder or replaces the clinician treating your mood. Every result goes to your physician, who decides what it means. What the numbers add is evidence about whether an inflamed, metabolically strained body sits underneath the symptom. For how results are read, see understanding your results.

Questions to bring, and what not to change

Has my CRP ever been measured, and if it was above 3 mg/L, was it repeated and explained?
What is my fasting insulin as a number, not only my glucose?
Can the clinician treating my gut and the one treating my mood see each other’s notes?
How many antibiotic courses have I had in recent years, and is that written into my history?

Nothing here is a reason to stop or adjust a psychiatric medication. That decision stays between you and the physician who prescribed it. Food still belongs in the conversation: in the SMILES trial of adults with major depression, remission rates were 32.3 percent with dietary support and 8.0 percent with social support. That sits alongside the prescription, not in place of it.

Every study behind these figures, including the genetic work that argues against this model, is laid out in the Chapter 1 Deep Dive for The Angry Gut by Dr. Gurpreet Singh Padda, MD, MBA, MHP, and Ami Michelle Grimes. If you missed the start of the series, read what a vagus nerve test can and cannot show, then continue to what else is in the pill you already take.

Frequently asked questions

Can inflammation cause anxiety?

It can contribute in some people. Endotoxin experiments lower mood in healthy volunteers, people who start out more anxious or stressed react more strongly, and in mice activated gut-lining cells produce anxiety-like behavior. It is not the cause for everyone, which is why measuring inflammation matters more than assuming it. Read what a test result can and cannot tell you.

What CRP level suggests low-grade inflammation?

Mood research commonly uses a CRP above 3 mg/L to define low-grade inflammation, and one anti-inflammatory trial found benefit only above 5 mg/L. Those are research cutoffs. CRP also rises with infection, injury or hard exercise, so a single high result should be repeated and explained before anyone reads meaning into it. See how to read your Measura report.

Does gut serotonin affect anxiety?

Not by traveling to the brain. Most serotonin is produced in the gut, yet that molecule is kept out of the brain by the blood-brain barrier. Gut signals reach the brain through vagal nerve fibers, and inflammation diverts tryptophan, the raw material the brain needs to make its own serotonin. Learn about autonomic symptoms and what they can signal.

Can Measura test for leaky gut or my microbiome?

No. Stool, breath and microbiome tests are separate services done elsewhere, and a widely used commercial zonulin kit was found to detect a different protein than the one named on its label. Measura measures metabolic and inflammatory blood markers, body composition, autonomic function and cognition, and reports them to your physician. See what Measura actually measures.

Should I stop my anxiety medication if my inflammation is high?

No. A raised inflammatory marker does not justify dropping or adjusting psychiatric treatment by yourself. The medication has a job, and any change is a decision with the physician who prescribed it. Measured inflammation adds a second line of work, often around insulin, weight and diet, rather than replacing the first. See insulin resistance and metabolic health.

Can stress cause inflammation?

Strain in daily life shows up in the blood. In healthy married couples, more hostile arguments went with more of a blood marker for bacterial fragments crossing the gut wall, and that marker tracked whole-body inflammation: 79 percent of people in its highest group had an average daytime CRP above 3, against 21 percent in its lowest. Diet adds fuel on top of that.

What blood test checks for inflammation?

The usual starting marker is C-reactive protein, or CRP, drawn as part of a laboratory panel chosen with your physician, often with fasting insulin beside it. One high CRP calls for a repeat, because infection, injury or a hard workout can also push it up. A blood test describes inflammation; it does not diagnose an anxiety disorder.

Can diet help with inflammation and anxiety?

Food belongs in the conversation. A food supply built on flour and sugar and stripped of fermentable fiber adds fuel to inflammation from the plate. In the SMILES trial of adults with major depression, remission rates were 32.3 percent with dietary support and 8.0 percent with social support. Diet sits alongside any prescription, never in place of it.

Find out whether inflammation is part of your picture

Ask your physician about metabolic and inflammatory blood work, body composition and autonomic testing, so the conversation about anxiety includes your own numbers.

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References

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