Is a gluten-free diet a healthy alternative for someone that doesn't have celiac disease?

Yes, but unnecessary: People who have no ill symptoms and no allergy to gluten don't benefit from a gluten-free diet. Gluten-free foods use grains such as corn, rice, millet, quinoa, and sorghum that don't have gluten, but such foods are more expensive and harder to find. However, healthy gluten-free foods are fine for anyone to eat, as long as they are part of a balanced diet.

Yes: There is a sizeable body of scientific evidence showing that grains, as well as legumes, contain anti-nutrients that may increase intestinal permeability and cause leaky gut and associated symptoms eliminating gluten-containing grains (and sugars) from your diet, while introducing traditionally fermented foods, can help prevent leaky gut as well as other chronic health conditions.

Certainly but....: ... For children this is an unbelievably restricted diet. It is very difficult to sdhere to.In a study where parents were asked whether medicine or the diet was effective, where both would work, the choice by the parents was the medicine by a clear margin.