MS, the gut, and Autism in males and females

 

There is quite a lot in this blog about MS (multiple sclerosis) because it is the classic myelin disorder and so is well researched. Many other neurological conditions, including some autism, also feature impaired myelination. 

One of the very cheap myelin therapies is the old anti-histamine drug Clemastine. I learnt this week that it will be trialed in children with Pitt Hopkins syndrome. It is a very logical choice and some parents have already trialed it. I used it for a few years and did feel there was a benefit. The key is to keep the dose low enough not to cause drowsiness. Very long term use may reduce acetylcholine in the brain, so it is not a forever medicine.

Then I saw some interesting research from Japan showing that it appears that multiple sclerosis starts in the gut.

We already know from interesting US research that you must have had the Epstein-Barr virus (EBV) to be able to develop MS. It also depends on the age at which you caught the virus. The older you were, the bigger the risk of later developing MS. So it is best to get EBV very young, or avoid it entirely by vaccination (expected to be available in 10 years). EBV is also known to increase the risk of certain cancers, so I guess the vaccination will get adopted.

 

The role of the gut

For years, researchers have suspected that the gut plays an important role in neurological conditions. What has been missing is a clear explanation, a step-by-step account of how something happening in the intestine could influence the brain.

A recent study provides exactly that for Multiple Sclerosis.

 

How Intestinal Cells Trigger Multiple Sclerosis

Summary: For years, scientists have suspected that the gut plays a role in Multiple Sclerosis (MS), but the “smoking gun” linking the two has been elusive. A landmark study has finally identified the cellular mechanism: Intestinal Epithelial Cells (IECs)—the cells lining your gut—are acting as “accidental” messengers.

The study found that in patients with MS, these gut cells abnormally express MHC II, a protein that “presents” antigens to the immune system. This interaction mistakenly transforms ordinary immune cells into pathogenic Th17 cells, which then migrate from the gut directly to the central nervous system to attack the brain and spinal cord.

Key Facts

·         The Accidental Messenger: IECs do not normally “talk” to the immune system in this way. In MS, they begin expressing MHC II, which “primes” CD4+ T cells to become aggressive.

·         The Th17 Migration: Using “Kaede” protein tracking (which changes colour under light), researchers proved that these gut-primed Th17 cells physically travel from the intestine to the spinal cord to drive neuroinflammation.

·         Human Connection: The team used single-cell RNA sequencing on human biopsies to confirm that the same inflammatory patterns seen in mouse models are present in the intestines of human MS patients.

·         New Treatment Target: Most current MS therapies target B cells in the blood; this study suggests that treating the gut environment or blocking the antigen-presenting activity of gut cells could stop MS at its source.

 

This new knowledge should shift the focus of treatment away from simply suppressing the immune system after damage has started, toward stopping the problem earlier at its source. Future therapies may aim to block these abnormal gut signals, target specific inflammatory pathways, and use gut-focused treatments such as microbiome modulation and diet. Overall, the goal is to prevent the immune system from being mis-trained in the first place, rather than just managing the consequences later.

  

The actual study:-

Intestinal epithelial MHC class II induces encephalitogenic CD4 T cells and initiates central nervous system autoimmunity

The gut as an immune training ground

The key finding is that cells lining the gut, intestinal epithelial cells, can act as unexpected immune instructors.

In MS, these cells begin expressing MHC class II, a molecule normally used by immune cells to “present” antigens. This abnormal behavior turns the gut lining into a kind of misguided training center.

The result is:

• Activation of Th17 cells
• These cells become highly inflammatory
• They migrate from the gut to the brain and spinal cord
• They drive autoimmune attack on myelin

This is a causal pathway from gut to brain.

 

A shared biological axis

The gut is not just influencing the brain, it is actively programming immune cells that control it.

This gut-immune-brain axis likely operates across multiple conditions, including autism, asthma, and ADHD.

 

Intestinal epithelial cells and autism

Intestinal epithelial cells sit at the center of the gut–immune interface and may also play a role in Autism.

They have three key functions.

 

1. Barrier control

IECs regulate what passes from the gut into the body.

If this barrier is altered, microbial products and metabolites may enter circulation and immune activation may increase

Some studies in autism report increased gut permeability, suggesting altered epithelial function.

 

2. Immune signaling

IECs actively communicate with the immune system. They release cytokines, influence T-cell behavior and potentially affect pathways like Th17 cells

In MS, abnormal IEC signaling directly drives inflammation.

In autism, similar immune pathways are implicated, though less directly established.

 

3. Microbiome interpretation

IECs “read” signals from gut microbes.

·        balanced microbiome produces healthy regulatory signals

·        dysbiosis produces inflammatory signals

 

In autism, microbiome differences are common, meaning IEC signaling may be altered.

 

Autism - same axis, different outcome

In autism, we see:

• altered microbiome
• gut inflammation
• immune activation (including Th17/IL-17 in some cases)

 

The difference is timing and target.

 

Step	MS (Adult)	Autism (Early Life)
Gut signal	IEC activation	Dysbiosis / gut inflammation
Immune response	Pathogenic Th17 cells	Altered immune signaling
Brain effect	Myelin attack	Developmental disruption
Timing	Adulthood	Early childhood

 

Why more females have MS

Multiple Sclerosis is 2–4 times more common in females.

Females have:

• stronger immune responses
• two X chromosomes (more immune genes)
• greater responsiveness to immune signals

When the gut sends the wrong signal, females are more likely to amplify it into autoimmunity.

Hormonal shifts (e.g., pregnancy/postpartum) further support an immune-driven mechanism.

 

Why more males have Autism

Severe autism is 3–4 times more common in males.

Males show:

• higher vulnerability during early brain development
• only one X chromosome (less genetic backup)
• less regulated early-life immune signaling

When the gut–immune system is activated early, males are more likely to cross the threshold into neurodevelopmental disruption.

Females appear more protected via:

• neural resilience
• better early immune regulation
• genetic redundancy

 

The EBV connection: a required trigger

One of the most important recent discoveries is the role of Epstein-Barr Virus infection in MS.

Large longitudinal studies show:

• individuals not infected with EBV almost never develop MS
• after EBV infection, the risk of MS increases dramatically (around 30-fold)

This suggests EBV is a necessary but not sufficient factor.

 

How EBV fits the model

EBV infects and persists in B cells, altering immune behavior. It may:

• create immune cells that recognize both viral proteins and brain proteins (molecular mimicry)
• keep B cells chronically activated
• prime the immune system toward autoimmunity

 

A multi-hit model of MS

The emerging picture is that MS requires multiple aligned factors:

1.     EBV infection
creates autoreactive immune potential

2.     Gut immune dysregulation
generates inflammatory Th17 cells

3.     Environmental modifiers (e.g., low vitamin D)
reduce immune regulation

Together, these drive immune attack on the brain

EBV loads the gun, the gut pulls the trigger, and the immune system fires at the brain.

 

Why MS varies by latitude

MS prevalence increases with distance from the equator.

• Lower rates near the equator
• Higher rates in northern regions

This reflects environmental effects on immune regulation.

 

Vitamin D and sunlight

Reduced sunlight lowers vitamin D, which normally:

• suppresses excessive Th17 cells activity
• promotes immune tolerance

Low vitamin D removes a key brake on autoimmunity.

 

Infection timing

Epstein-Barr Virus infection often occurs later in higher latitude regions, triggering stronger immune responses.

 

Microbiome differences

Geography affects diet and microbial exposure, shaping the gut–immune axis.

 

Hygiene effects

Reduced early microbial exposure may impair immune training.

 

Why some conditions improve with age

A striking observation across medicine is that many children “grow out of” certain conditions.

This includes:

• Mild autism (in some cases)
• Asthma
• Attention Deficit Hyperactivity Disorder

This reflects a shared biological pattern.

 

The dynamic regulation model

Early life is a period of high instability:

• the gut barrier is still developing
• the microbiome is fluctuating
• the immune system is learning tolerance
• the brain is highly sensitive

This creates a system that is:

• more reactive
• more inflammatory
• more vulnerable

 

What Changes Over Time

Three stabilizing processes occur:

1. Gut stabilization

• microbiome becomes more consistent
• fewer abnormal immune triggers

2. Immune regulation improves

• better control of inflammation
• reduced overactivation (including Th17 pathways)

3. Brain maturation

• circuits strengthen
• compensatory pathways develop
• regulation improves

 

The threshold effect

Symptoms can be viewed as crossing a threshold:

• Above threshold → visible condition
• Below threshold → mild or no symptoms

As stability improves:

• inflammation ↓
• regulation ↑

The individual may drop below the clinical threshold (unless they keep lowering the diagnostic threshold, as with autism)

 

Implications for Treatment

Focus on stabilizing the system, not just suppressing symptoms.

Potential approaches:

• improve gut health and microbiome stability
• reduce inappropriate immune activation
• support metabolic resilience
• ensure adequate vitamin D and environmental exposure
• minimize chronic inflammatory triggers

 

For MS:

• targeting EBV and gut immune programming may prevent disease at its source

 

For autism and related conditions:

• early stabilization of the gut–immune axis may improve outcomes

 

Does severe autism improve with age?

Severe autism is not a fixed condition where everything is determined at the start of life. While some children begin with greater challenges than others, what happens over time depends heavily on how skills develop during the long period of childhood and adolescence. These include communication, social interaction, emotional regulation, and daily living abilities. Early progress in these areas can create a positive ripple effect, making future learning easier and more natural.

If certain skills are delayed or missed early on, development may be slower—but this does not mean progress is impossible. The brain remains capable of learning and adapting, even later in life. This means that outcomes are not set in stone, much is up to the parents.

What shapes these outcomes is a combination of factors. Biology plays an important role—things like brain plasticity, energy levels, and overall health can influence how easily a child can learn. Biology can be modified pharmacologically, which is what EpiphanyASD is all about.

Biology is only part of the picture. Therapy, education, and the home environment are equally important. Structured teaching, repetition, encouragement, and meaningful interaction all create opportunities for skills to develop.

Importantly, these factors interact with each other. When a child’s biological state improves, they become more receptive to learning. In turn, effective therapy and support can help build new abilities, which further improves confidence, behavior, and engagement. This creates a positive cycle where progress builds on progress. Nothing changes over night, it is a slow process. Increasing skill acquisition rate by just 10% can lead to a massive difference over a decade.

This is why outcomes in autism are so variable. Two children who start at a similar level can follow very different paths depending on the opportunities they have and how their abilities are supported over time.

There are also important developmental windows, particularly in early childhood, when learning certain skills is easier. However, these windows do not fully close. Progress may become slower later, but it is still very much possible. Many individuals continue to gain skills well into adolescence and adulthood.

In this way, severe autism is better understood as a dynamic developmental process rather than a fixed outcome. The trajectory can be changed, sometimes substantially, depending on how biology, learning, and environment come together over time.

 

A note on EBV

Epstein–Barr virus (EBV), also known as human herpesvirus 4, is a common virus that infects most people and remains in the body for life. It is best known for causing infectious mononucleosis (“glandular fever”), especially when infection occurs in adolescence.

EBV spreads via saliva.

Childhood transmission is very common globally, but as hygiene increases it gets caught at older ages. In western countries kissing during adolescence is a major route.

90-95% of adults carry the EBV, the only question is at what age they were exposed.

Early exposure to EBV is less risky than late exposure. This fits the hygiene hypothesis, which has been covered in this blog and my book.

The hygiene hypothesis proposes that reduced exposure to microbes in early life results in less “training” of the immune system and causes higher risk of immune dysregulation in later life.

Exposure to pets at home will help train a young child’s immune system, but does not expose him/her to EBV, which is exclusively a human virus.