PHGG and acacia fibre are both gentle soluble fibres, but they are not identical.
PHGG comes from guar gum that has been partially broken down to improve solubility and reduce thickness. It is often used in gut health products because it mixes well and is discussed for prebiotic support. Acacia fibre comes from acacia tree sap and has a light, neutral character. It is also used as a prebiotic fibre and is valued for easy daily use.
Compared with psyllium husk, both are usually less thick. That means they may suit people who dislike gel texture. But lower thickness also means they do not do the same job as psyllium in stool bulk or satiety. Different fibres have different strengths.
For tolerance, both should still be started slowly. A gentle fibre can still cause gas if the dose is too high or the gut is not used to fermentable fibre. People with sensitive digestion should introduce one change at a time.
Choose PHGG or acacia based on purpose, taste, mixing and how your stomach responds. Do not choose by trend.
A good fibre routine is not about finding the most famous ingredient. It is about finding the fibre behaviour you can use daily.