【醫生信箱】ASD小朋友服用益生菌是否合適？

Q63. 孩子5歲，high functioning ASD，請問服用lactobacillus reuteri是否合適？本身有食PS 128。

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Ans.

益生菌與自閉症

益生菌的初始理念：腸道-大腦軸線

最初將益生菌用於自閉症（ASD）的想法是基於「腸道-大腦軸線」理論，即消化系統與大腦之間存在著持續的雙向溝通，影響著我們的功能。同時，許多患有自閉症的兒童也經常經歷頻繁的腸胃道問題，例如便秘、腹瀉和腹痛。

該理論認為：腸道菌群的失衡會導致發炎，進而影響大腦，並使自閉症症狀惡化。理論上，調整這種菌群平衡應有助於重新平衡 腸道-大腦軸線。

整體結果令人失望

目前，科學界還是沒有在高階的研究結果中找到很多支持益生菌的數據。當研究者在系統性回顧（一種很強的研究數據統合方式）中綜合多項研究數據時，他們發現益生菌並不能對自閉症的核心症狀（如社交溝通或重複性行為）產生顯著的改變。這項證據概括了益生菌並不是有效治療自閉症的基礎療法。

小型研究 數據

今天所討論的兩種益生菌菌株在小規模的試驗中顯示出對某些特定行為/指標有所幫助：

1. 植物乳桿菌 PS128 (Lactobacillus plantarum PS128)

   一項在台灣進行（80位兒童）的隨機對照試驗 (RCT) 研究了此菌株。對於自閉症治療的研究來說，這是比較小的先導研究。

   關鍵發現： PS128 並未顯著改善整體自閉症的嚴重程度。然而，該研究發現特別是在年齡較小的參與者中，在對抗/違抗行為方面有著有限的改善，。這表明它可能在管理具挑戰性的行為和情緒調節方面發揮潛在作用，而不是核心的社交挑戰。

   
   

2. 羅伊氏乳桿菌 (Lactobacillus reuteri)

   其他試驗之所以關注羅伊氏乳桿菌，是因為它可能與催產素（有時被稱為「社交荷爾蒙」）有關聯。一項先導研究測試了兩種羅伊氏乳桿菌菌株的特定組合，僅涉及 43 名自閉症兒童（其中 21 名接受益生菌）。

   關鍵發現： 與 PS128 相似，這種干預並未改變整體自閉症的嚴重程度。然而，它顯示出社交溝通方面有雖小但具統計學意義的改善。

結論：證據有限，但風險偏低

現時，支持常規使用益生菌作為自閉症核心症狀主要療法的高品質證據非常有限。

然而，由於益生菌通常副作用極小（一般只是輕微的脹氣或腹脹），父母可以選擇嘗試使用某種特定的菌株，進行一個明確的試用期（例如 2-3 個月），以觀察它是否對特定的問題有所幫助，例如：

1. 慢性便秘或腹瀉。

2. 對抗或違抗行為（可能與 PS128 有關）。

3. 社交溝通技巧（可能與Lactobacillus reuteri有關）。

如果您在短期試用後沒有看到清晰的益處，那麼最好的決定就是停止該療法。

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Probiotics for Autism: What the Evidence Says

The initial idea behind probiotics use in autism is based on the "gut-brain axis" theory  that a constant, two-way line of communication between the digestive system and the brain affects our functioning. We know that many children with ASD also experience frequent and often severe gastrointestinal issues like chronic constipation, diarrhea, and abdominal pain. The theory is that imbalance of bacteria in the gut contributes to inflammation, which affects the brain and worsening ASD symptoms. Theoretically, modifying this balance should help re-balance the gut-brain axis.

The Big Picture: Overall Results Are Disappointing

While the rationale is compelling, the results from high-level research have been disappointing. When researchers pool the data from multiple studies in a systematic review, they are able to balance out positive and negative findings. They find that probiotics, in general, do not cause a significant, reliable change in the core symptoms of ASD (like social communication or repetitive behaviors). This evidence suggests that probiotics are not a broad treatment for the condition itself.

The Small Studies: Signs of Specific, Limited Benefit

Despite the overall negative picture, the two specific probiotic strains discussed, have shown some benefit in very small-scale trials, suggesting they might help with some specific behaviours even if they don't change the overall diagnosis.

1. Lactobacillus plantarum PS128

A randomized controlled trial (RCT) in Taiwan investigated this strain. The study planned for 80 children, which is considered a small pilot study for a complex condition like ASD.

• Key Findings: PS128 did not significantly improve total autism severity. However, the study found limited improvements in opposition/defiance behaviors, particularly in the younger participants. This suggests a potential role in managing challenging behaviors and emotional regulation rather than core social challenges.

2. Lactobacillus reuteri

Other trials have focused on L. reuteri because of its potential link to oxytocin—sometimes called the "social hormone." One pilot study testing a specific combination of two L. reuteri strains involved only 43 autistic children (21 receiving the probiotic), making it an extremely limited dataset.

• Key Findings: Similar to PS128, this intervention did not alter overall autism severity or repetitive behaviors. However, it did show a small but statistically significant improvement in social communication. 

Conclusion: Limited Evidence but Low Risk Intervention

There is very limited high-quality evidence to support the routine use of probiotics as a primary treatment for the core symptoms of ASD.

However, since probiotics are generally safe and have minimal side effects (usually only minor gas or bloating), a parent may choose to try a specific, well-researched strain for a defined period (e.g., 2–3 months) to see if it helps with a specific, targeted issue like:

• Chronic constipation or diarrhea.

• Oppositional or defiance behaviour (may be linked to PS128).

• Social Communication skills (may be linked to L. reuteri).

If you do not see a clear, measurable benefit after a short trial, the most evidence-based decision would be to stop the treatment.

✍🏻撰文：精神科專科醫生 王崇瀚醫生