A Broth & Co guide to immune signalling, inflammation, repair, gut health, movement, metabolism and healthy ageing.

When most people picture the immune system, they imagine an army: white blood cells attacking, antibodies recognising threats and immune cells destroying infected cells. That picture is useful, but it misses the part that makes the whole system work.

Before an immune response can be coordinated, cells need to communicate. One cell needs to say that something has happened. Other cells need to know where to go. Some signals need to increase activity, while others need to restrain it. Later, the body needs signals that help resolve the response and support tissue repair.

Much of that communication depends on tiny signalling proteins called cytokines. You may recognise names such as IL-6, IL-1 beta, IL-10, TNF-alpha and interferons. They are often described as inflammatory markers, but that is only part of the story.

 

Your Immune System Is a Communication Network

A better mental model for the immune system is not just an army. It is an information network. Billions of cells continually exchange messages so the body can detect change, respond appropriately and return towards balance when the job is done.

Cytokines form one of the languages used in that network. A cell detects something in its environment. It releases a cytokine. Another cell with the right receptor receives the message. That receiving cell then changes its behaviour.

 

This idea connects naturally with The Immune System Explained: How Your Body Protects, Learns & Repairs Throughout Life, Cellular Signalling Explained: How Your Cells Know When to Repair, Grow and Recover and The Hidden Conversations Inside Your Body: How Cells, Hormones & the Gut Microbiome Work Together..

What Is a Cytokine?

A cytokine is a small signalling protein released by cells to influence the behaviour of other cells, or sometimes the same cell that produced it. Some act locally within a tissue. Others can contribute to wider body-level responses.

The word cytokine covers several families of signalling molecules. These include interleukins, chemokines, interferons and tumour necrosis factor family members. The names can sound intimidating, but the idea is simple: cells need messages, and cytokines help carry those messages.

Another common misconception is that cytokines are produced only by immune cells. Immune cells are major cytokine producers, but they are not alone. Epithelial cells, endothelial cells, fibroblasts, adipose tissue, skeletal muscle and cells within the nervous system can all participate in immune-related signalling.

 

Cytokines Are a Language, Not a Single Alarm

Imagine trying to run an entire city with only one message: ACTIVATE. Emergency services, hospitals, traffic control, repair crews and community services all need different information. The immune system faces the same problem.

Some cytokines help activate immune responses. Some influence immune-cell growth. Some help recruit cells to a particular tissue. Some coordinate antiviral defence. Some participate in tissue repair. Others help regulate or restrain inflammatory activity.

The immune system does not need one signal. It needs a language.

 

 

Why Good and Bad Cytokines Is Too Simple

Health articles often divide cytokines into two neat groups: pro-inflammatory equals bad, anti-inflammatory equals good. Biology is not that tidy.

Inflammatory signalling can be exactly what the body needs. If bacteria enter a wound, immune cells need to be recruited. If tissue is damaged, repair processes need to begin. If a virus infects cells, antiviral defence needs to be coordinated.

The problem is not inflammation itself. Problems can arise when immune signalling is inappropriate, excessive, poorly regulated or fails to resolve.

IL-6 is a useful example. IL-6 can participate in inflammatory responses, but contracting skeletal muscle can also release IL-6 during exercise. In that context, IL-6 forms part of the signalling response to physical activity. The same named molecule can appear in infection, exercise, metabolic signalling and tissue stress. Context changes interpretation.

For more on this nuance, read Inflammation Explained: Understanding the Body's Natural Response to Injury, Infection & Repair and Muscle as an Endocrine Organ: How Myokines Influence Metabolism, Inflammation & Healthy Ageing.

Inflammation Through the Lens of Cytokines

Inflammation has become one of the most negatively charged words in wellness. But without inflammation, a paper cut could become dangerous, infection could spread unchecked and damaged tissue would struggle to repair itself.

Acute inflammation usually follows a biological arc: recognition, activation, recruitment, response, regulation, resolution and repair. Cytokines help coordinate each stage. Chemokines help tell immune cells where to go. Regulatory signals help prevent the response from escalating forever.

Resolution is not simply the absence of inflammation. It is an active process. Immune-cell populations change, debris is cleared, tissue-repair programmes become more prominent and normal function is gradually restored.

 

 

Persistent low-grade inflammatory activity is a different discussion. Chronic Inflammation Explained: Diet, Lifestyle, Gut Health & Everyday Wellbeing and What Is Inflammaging? | Understanding Age-Related Inflammation explain that longer-term context in more detail.

Cytokines, the Gut and the Microbiome

The gastrointestinal tract is one of the body's busiest immune communication hubs. Every day it encounters food, resident microorganisms, microbial metabolites, microbial cell components and potential pathogens.

The immune system must continually interpret this information. Should it tolerate it? Monitor it? Respond? Recruit additional cells? Resolve the response? Cytokines help coordinate these decisions.

The cells lining the gut are not passive spectators. Intestinal epithelial cells can detect microbial and environmental signals, communicate with immune cells and receive signals in return. The microbiome produces compounds, including short-chain fatty acids and other metabolites, that can interact with host cells and influence signalling pathways.

This does not mean gut bacteria directly control immunity. It means the gut ecosystem contributes biological information that the body interprets as part of a larger communication network.

For the bigger gut connection, read The Gut-Brain-Immune Connection: How Your Gut Influences Whole-Body Health, The Gut-Brain Axis Explained, The Complete Guide to Gut Biotics. and Microbiome Diversity Explained: Why Variety Is One of the Best Things You Can Feed Your Gut.

Cytokines Beyond Immunity: Muscle, Fat, Brain and Ageing

Once cytokines are understood as communication molecules rather than simply inflammatory markers, something remarkable becomes clear. They are woven throughout the body.

Skeletal muscle releases signalling molecules during contraction. Many are described as myokines. Some myokines influence local muscle adaptation; others participate in communication with the liver, fat tissue, bone, immune system and brain. This is one reason physical activity has effects far beyond the muscles doing the work.

Adipose tissue also communicates. Fat tissue is metabolically active and can release signalling molecules involved in appetite, energy metabolism, insulin sensitivity and immune signalling. This creates one of the bridges between metabolic health and immune biology.

The brain and immune system also exchange information. During infection, immune signalling can influence fatigue, appetite, motivation, sleep and body temperature. These changes are not necessarily random symptoms. They can be part of a coordinated physiological response.

For related whole-body context, read The Body's Chemical Messengers: How Hormones Guide Health Throughout Life, Sleep, Gut Health & Brain Function and Stress, the Gut & Cognitive Function.

Cytokines and Healthy Ageing

Ageing brings another layer of complexity. Immune-cell populations change. Mitochondrial function changes. Cellular senescence, body composition, metabolism, gut microbial ecology and tissue repair all shift over time.

Researchers use the term immunosenescence to describe age-associated changes in immune function. Inflammaging describes the tendency towards persistent low-grade inflammatory activity that can be observed with ageing. Cytokines participate in these patterns, but they do not explain ageing alone.

One fascinating example is cellular senescence. Senescent cells no longer divide normally, but they can remain metabolically active. Some release collections of signalling molecules, including cytokines, called the senescence-associated secretory phenotype. A change inside one cell can alter the environment around many others.

For more, read Healthy Ageing, Immunosenescence & Gut Health Explained and The Science of Inflammaging: How Diet, Movement & Gut Health Influence Healthy Ageing.

Cytokines as Biomarkers: What a Change Actually Means

Cytokines can tell scientists that something has changed, but they do not always tell us what that change means for a person's health.

A biomarker is a measurable biological characteristic that provides information about a physiological process. Cytokines can be useful biomarkers because they allow researchers to observe aspects of immune signalling. But a biomarker is not automatically the outcome that matters to a person.

Think of a biomarker like a dashboard light in a car. The light tells you something changed. It does not explain the whole story by itself. You still need context: what the marker measures, why it changed, how large the change was, how long it lasted and whether it affected function or wellbeing.

 

This is why a headline claiming that a food or ingredient reduced inflammatory cytokines needs context. Which cytokines? In whom? Compared with what? For how long? Were levels elevated to begin with? Did the change correspond with a meaningful outcome?

Good science communication preserves the difference between biological activity and a proven health benefit.

Nutrition Supports Immune Regulation

Nutrition plays an essential role in immune biology. Immune cells require energy. They require amino acids to build proteins. Cell membranes require lipids. DNA synthesis and antioxidant systems require micronutrients.

Protein is particularly fundamental. Cytokines are proteins. Antibodies are proteins. Many receptors and enzymes are proteins. Immune cells continually synthesise and remodel proteins as they respond to changing conditions.

This does not mean that more of every nutrient keeps making the immune system stronger. Adequacy matters. Deficiency can impair function. Excess is not automatically beneficial. The most useful everyday frame is a varied food-first diet that supplies protein, colourful plants, fibre, healthy fats, fluids and micronutrients consistently.

For more on protein and amino acids, read Protein Throughout Life: Why Your Protein Needs Change With Age, Amino Acids The Building Blocks and High-Protein Foods: The Foundation of Muscle, Healthy Ageing & Recovery Nutrition.

Where Bone Broth Fits

Bone broth is best understood as one food within a broader dietary pattern, not a shortcut to immune health. Broth & Co bone broth can contribute naturally occurring protein, collagen-derived amino acids and savoury hydration, and it can make soups, stews, sauces, rice dishes and vegetable-rich meals more practical.

That role is simple but useful. A warm cup of broth or a broth-based meal can help people build more nourishing routines around whole foods, protein, vegetables, herbs and spices.

For more, read Bone Broth Benefits: The Complete Guide to Gut Health, Protein, Recovery & Healthy Ageing and Bone Broth, Digestive Wellbeing & Inflammation: A Food-First Approach.

Where Beta-Glucans and Mushrooms Fit

Beta-glucans are naturally occurring polysaccharides found in foods such as mushrooms, oats, barley and yeast. They are studied because of the way certain beta-glucans can interact with immune cells and pattern-recognition pathways.

That does not make mushrooms miracle foods. It does make them interesting whole-food ingredients within a varied dietary pattern. Shiitake, agaricus and other mushrooms bring flavour, fibre-like compounds, micronutrients and bioactive polysaccharides into everyday meals.

For more, read Beta-Glucans Explained: Benefits for Immunity, Gut Health, Cholesterol, Brain Health & Functional Nutrition, Shiitake Mushrooms: Benefits for Brain Health, Gut Health & Healthy Ageing, Agaricus Mushrooms Explained and Energy Performance Bone Broth Powder is a functional food.

A Simple Immune Communication Framework

The goal is not to suppress every cytokine or push every immune marker higher. The goal is to support the wider biological environment in which immune regulation occurs.

 

Try the Recipes

For practical meals that bring together broth, vegetables, herbs, spices and whole foods, explore Broth & Co's recipe collection.

collection of nourishing recipes and The Power of Soup: How One Pot Can Support Immune Health, Eat More Vegetables & Reduce Food Waste are useful places to start.

Frequently Asked Questions

What are cytokines?

Cytokines are small signalling proteins used by immune cells and many other cell types to communicate. They can influence immune activation, cell recruitment, inflammation, tissue repair, regulation and resolution.

Are cytokines the same as inflammation?

No. Cytokines can participate in inflammatory signalling, but inflammation is a larger biological process involving immune cells, blood vessels, tissues and many signalling molecules.

Are cytokines good or bad?

Neither label is very useful. Cytokines perform essential biological functions. Their effects depend on where they are produced, which cells receive the signal, timing, concentration, duration and the wider biological environment.

What are pro-inflammatory cytokines?

The term usually describes cytokines involved in initiating or amplifying aspects of inflammatory responses. Examples often discussed include IL-1 beta, IL-6 and TNF-alpha. They are not automatically harmful; context matters.

What are anti-inflammatory cytokines?

Some cytokines participate in regulating or restraining inflammatory responses. IL-10 is one commonly discussed example, although immune regulation involves many interacting signals rather than one simple anti-inflammatory switch.

What are chemokines?

Chemokines are signalling molecules that help guide immune-cell movement. They can create chemical gradients that tell immune cells where they are needed.

Why does exercise affect cytokines?

Exercise challenges muscle, metabolism and connective tissue. Contracting muscle releases signalling molecules called myokines, some of which are cytokines. This is one way movement communicates with the rest of the body.

Can food change cytokine levels?

Dietary patterns and nutritional interventions can influence immune and metabolic physiology, and researchers sometimes measure cytokines in these studies. A cytokine change still needs context before it can be interpreted as meaningful.

Does a lower inflammatory marker mean better health?

Not necessarily. Researchers consider the marker, baseline level, population, size of change, duration, study design and whether the change is linked with meaningful outcomes.

How does gut health relate to cytokines?

The gut is a major immune interface. Epithelial cells, immune cells, microbial metabolites and the intestinal barrier all participate in signalling, and cytokines help coordinate parts of that conversation.

Summary

Cytokines are not simply inflammatory chemicals circulating through the body. They are messengers. They help cells exchange information, recruit assistance, coordinate defence, support repair, regulate responses and resolve immune activity when the work is done.

Their influence extends far beyond what we traditionally call the immune system. Muscle communicates through cytokines. The gut participates in cytokine signalling. Adipose tissue communicates. The nervous system interacts with immune signals. Ageing changes the network. The microbiome contributes another layer of biological information.

A higher number is not automatically worse. A lower number is not automatically better. Changing one cytokine does not mean the entire immune system has been boosted or that inflammation has been eliminated.

The deeper lesson is more useful: healthy immunity depends on communication, regulation and the ability to adapt. Cytokines help make that extraordinary coordination possible.

Selected Research Context

Cytokines are widely recognised as secreted signalling molecules that allow immune cells and other cell types to communicate through receptor-mediated pathways.

Exercise can alter cytokine and myokine patterns, with IL-6 frequently discussed as an example of context-dependent signalling from contracting skeletal muscle.

Inflammation involves coordinated activation, recruitment, regulation and resolution rather than a single harmful state.

Cytokines can be useful biomarkers in research, but biomarker changes require context before they can be interpreted as health outcomes.