The verb 'help' takes both a to-infinitive and a bare infinitive, but the bare infinitive is said to be more common in casual style, and that's what's used in this example sentence.
Literal
Verb help [topic-は] to-infinitive and bare-infinitive [of-の] both [object-を] takes[but-が], casual style [at-では] bare-infinitive [subject-が] many [quotative-と] is-said-[progressive-ており], this example-sentence [even-でも] that [subject-が] is-used.
Educational grammar-explanation register. Mixes Japanese sentence structure with English grammatical terminology (to不定詞 = to-infinitive, 原形不定詞 = bare infinitive) and inline English word help. ~とされている is a formal passive construction 'it is said / it is considered' — marking a general claim without attributing it to a specific speaker. ~ており is the formal linking form of ~ている. A dense compound sentence typical of test-prep commentary on English grammar.